linux: Fix callbacks to CefPrintHandler (fixes #3729)

Out-of-process printing must also be disabled by passing
`--disable-features=EnableOopPrintDrivers`.

cef_paths2.gypi

@@ -288,6 +288,8 @@
       'tests/cefclient/browser/urlrequest_test.h',
       'tests/cefclient/browser/views_menu_bar.cc',
       'tests/cefclient/browser/views_menu_bar.h',
+      'tests/cefclient/browser/views_overlay_browser.cc',
+      'tests/cefclient/browser/views_overlay_browser.h',
       'tests/cefclient/browser/views_overlay_controls.cc',
       'tests/cefclient/browser/views_overlay_controls.h',
       'tests/cefclient/browser/views_style.cc',

include/capi/cef_browser_capi.h

@@ -33,7 +33,7 @@
 // by hand. See the translator.README.txt file in the tools directory for
 // more information.
 //
-// $hash=7c786570b1c7af912a31c6f0c3d742e8aeb38fd8$
+// $hash=e9f34d90eb4af614e35cbb29da0639b62acec7fd$
 //
 
 #ifndef CEF_INCLUDE_CAPI_CEF_BROWSER_CAPI_H_
@@ -301,29 +301,62 @@ typedef struct _cef_browser_host_t {
       struct _cef_browser_host_t* self);
 
   ///
-  /// Request that the browser close. The JavaScript 'onbeforeunload' event will
-  /// be fired. If |force_close| is false (0) the event handler, if any, will be
-  /// allowed to prompt the user and the user can optionally cancel the close.
-  /// If |force_close| is true (1) the prompt will not be displayed and the
-  /// close will proceed. Results in a call to
-  /// cef_life_span_handler_t::do_close() if the event handler allows the close
-  /// or if |force_close| is true (1). See cef_life_span_handler_t::do_close()
-  /// documentation for additional usage information.
+  /// Request that the browser close. Closing a browser is a multi-stage process
+  /// that may complete either synchronously or asynchronously, and involves
+  /// callbacks such as cef_life_span_handler_t::DoClose (Alloy style only),
+  /// cef_life_span_handler_t::OnBeforeClose, and a top-level window close
+  /// handler such as cef_window_delegate_t::CanClose (or platform-specific
+  /// equivalent). In some cases a close request may be delayed or canceled by
+  /// the user. Using try_close_browser() instead of close_browser() is
+  /// recommended for most use cases. See cef_life_span_handler_t::do_close()
+  /// documentation for detailed usage and examples.
+  ///
+  /// If |force_close| is false (0) then JavaScript unload handlers, if any, may
+  /// be fired and the close may be delayed or canceled by the user. If
+  /// |force_close| is true (1) then the user will not be prompted and the close
+  /// will proceed immediately (possibly asynchronously). If browser close is
+  /// delayed and not canceled the default behavior is to call the top-level
+  /// window close handler once the browser is ready to be closed. This default
+  /// behavior can be changed for Alloy style browsers by implementing
+  /// cef_life_span_handler_t::do_close(). is_ready_to_be_closed() can be used
+  /// to detect mandatory browser close events when customizing close behavior
+  /// on the browser process UI thread.
   ///
   void(CEF_CALLBACK* close_browser)(struct _cef_browser_host_t* self,
                                     int force_close);
 
   ///
-  /// Helper for closing a browser. Call this function from the top-level window
-  /// close handler (if any). Internally this calls CloseBrowser(false (0)) if
-  /// the close has not yet been initiated. This function returns false (0)
-  /// while the close is pending and true (1) after the close has completed. See
-  /// close_browser() and cef_life_span_handler_t::do_close() documentation for
-  /// additional usage information. This function must be called on the browser
-  /// process UI thread.
+  /// Helper for closing a browser. This is similar in behavior to
+  /// CLoseBrowser(false (0)) but returns a boolean to reflect the immediate
+  /// close status. Call this function from a top-level window close handler
+  /// such as cef_window_delegate_t::CanClose (or platform-specific equivalent)
+  /// to request that the browser close, and return the result to indicate if
+  /// the window close should proceed. Returns false (0) if the close will be
+  /// delayed (JavaScript unload handlers triggered but still pending) or true
+  /// (1) if the close will proceed immediately (possibly asynchronously). See
+  /// close_browser() documentation for additional usage information. This
+  /// function must be called on the browser process UI thread.
   ///
   int(CEF_CALLBACK* try_close_browser)(struct _cef_browser_host_t* self);
 
+  ///
+  /// Returns true (1) if the browser is ready to be closed, meaning that the
+  /// close has already been initiated and that JavaScript unload handlers have
+  /// already executed or should be ignored. This can be used from a top-level
+  /// window close handler such as cef_window_delegate_t::CanClose (or platform-
+  /// specific equivalent) to distringuish between potentially cancelable
+  /// browser close events (like the user clicking the top-level window close
+  /// button before browser close has started) and mandatory browser close
+  /// events (like JavaScript `window.close()` or after browser close has
+  /// started in response to [Try]close_browser()). Not completing the browser
+  /// close for mandatory close events (when this function returns true (1))
+  /// will leave the browser in a partially closed state that interferes with
+  /// proper functioning. See close_browser() documentation for additional usage
+  /// information. This function must be called on the browser process UI
+  /// thread.
+  ///
+  int(CEF_CALLBACK* is_ready_to_be_closed)(struct _cef_browser_host_t* self);
+
   ///
   /// Set whether the browser is focused.
   ///

include/capi/cef_life_span_handler_capi.h

@@ -33,7 +33,7 @@
 // by hand. See the translator.README.txt file in the tools directory for
 // more information.
 //
-// $hash=5232dd6bf16af9b6d195a47bb41de0dfb880a65e$
+// $hash=6aad2ccf30a6c519bbeee64d83866e82a41a48d8$
 //
 
 #ifndef CEF_INCLUDE_CAPI_CEF_LIFE_SPAN_HANDLER_CAPI_H_
@@ -138,35 +138,44 @@ typedef struct _cef_life_span_handler_t {
                                        struct _cef_browser_t* browser);
 
   ///
-  /// Called when a browser has received a request to close. This may result
-  /// directly from a call to cef_browser_host_t::*close_browser() or indirectly
-  /// if the browser is parented to a top-level window created by CEF and the
-  /// user attempts to close that window (by clicking the 'X', for example). The
-  /// do_close() function will be called after the JavaScript 'onunload' event
-  /// has been fired.
+  /// Called when an Alloy style browser is ready to be closed, meaning that the
+  /// close has already been initiated and that JavaScript unload handlers have
+  /// already executed or should be ignored. This may result directly from a
+  /// call to cef_browser_host_t::[Try]close_browser() or indirectly if the
+  /// browser's top-level parent window was created by CEF and the user attempts
+  /// to close that window (by clicking the 'X', for example). do_close() will
+  /// not be called if the browser's host window/view has already been destroyed
+  /// (via parent window/view hierarchy tear-down, for example), as it is no
+  /// longer possible to customize the close behavior at that point.
   ///
-  /// An application should handle top-level owner window close notifications by
-  /// calling cef_browser_host_t::try_close_browser() or
+  /// An application should handle top-level parent window close notifications
+  /// by calling cef_browser_host_t::try_close_browser() or
   /// cef_browser_host_t::CloseBrowser(false (0)) instead of allowing the window
   /// to close immediately (see the examples below). This gives CEF an
-  /// opportunity to process the 'onbeforeunload' event and optionally cancel
+  /// opportunity to process JavaScript unload handlers and optionally cancel
   /// the close before do_close() is called.
   ///
-  /// When windowed rendering is enabled CEF will internally create a window or
-  /// view to host the browser. In that case returning false (0) from do_close()
-  /// will send the standard close notification to the browser's top-level owner
-  /// window (e.g. WM_CLOSE on Windows, performClose: on OS X, "delete_event" on
-  /// Linux or cef_window_delegate_t::can_close() callback from Views). If the
-  /// browser's host window/view has already been destroyed (via view hierarchy
-  /// tear-down, for example) then do_close() will not be called for that
-  /// browser since is no longer possible to cancel the close.
+  /// When windowed rendering is enabled CEF will create an internal child
+  /// window/view to host the browser. In that case returning false (0) from
+  /// do_close() will send the standard close notification to the browser's top-
+  /// level parent window (e.g. WM_CLOSE on Windows, performClose: on OS X,
+  /// "delete_event" on Linux or cef_window_delegate_t::can_close() callback
+  /// from Views).
   ///
-  /// When windowed rendering is disabled returning false (0) from do_close()
-  /// will cause the browser object to be destroyed immediately.
+  /// When windowed rendering is disabled there is no internal window/view and
+  /// returning false (0) from do_close() will cause the browser object to be
+  /// destroyed immediately.
   ///
-  /// If the browser's top-level owner window requires a non-standard close
+  /// If the browser's top-level parent window requires a non-standard close
   /// notification then send that notification from do_close() and return true
-  /// (1).
+  /// (1). You are still required to complete the browser close as soon as
+  /// possible (either by calling [Try]close_browser() or by proceeding with
+  /// window/view hierarchy tear-down), otherwise the browser will be left in a
+  /// partially closed state that interferes with proper functioning. Top-level
+  /// windows created on the browser process UI thread can alternately call
+  /// cef_browser_host_t::is_ready_to_be_closed() in the close handler to check
+  /// close status instead of relying on custom do_close() handling. See
+  /// documentation on that function for additional details.
   ///
   /// The cef_life_span_handler_t::on_before_close() function will be called
   /// after do_close() (if do_close() is called) and immediately before the
@@ -182,22 +191,26 @@ typedef struct _cef_life_span_handler_t {
   /// which sends a close notification
   ///     to the application's top-level window.
   /// 2.  Application's top-level window receives the close notification and
-  ///     calls TryCloseBrowser() (which internally calls CloseBrowser(false)).
+  ///     calls TryCloseBrowser() (similar to calling CloseBrowser(false)).
   ///     TryCloseBrowser() returns false so the client cancels the window
   ///     close.
   /// 3.  JavaScript 'onbeforeunload' handler executes and shows the close
   ///     confirmation dialog (which can be overridden via
   ///     CefJSDialogHandler::OnBeforeUnloadDialog()).
   /// 4.  User approves the close. 5.  JavaScript 'onunload' handler executes.
-  /// 6.  CEF sends a close notification to the application's top-level window
-  ///     (because DoClose() returned false by default).
-  /// 7.  Application's top-level window receives the close notification and
+  /// 6.  Application's do_close() handler is called and returns false (0) by
+  ///     default.
+  /// 7.  CEF sends a close notification to the application's top-level window
+  ///     (because DoClose() returned false).
+  /// 8.  Application's top-level window receives the close notification and
   ///     calls TryCloseBrowser(). TryCloseBrowser() returns true so the client
   ///     allows the window close.
-  /// 8.  Application's top-level window is destroyed. 9.  Application's
-  /// on_before_close() handler is called and the browser object
+  /// 9.  Application's top-level window is destroyed, triggering destruction
+  ///     of the child browser window.
+  /// 10. Application's on_before_close() handler is called and the browser
+  /// object
   ///     is destroyed.
-  /// 10. Application exits by calling cef_quit_message_loop() if no other
+  /// 11. Application exits by calling cef_quit_message_loop() if no other
   /// browsers
   ///     exist.
   ///
@@ -215,13 +228,17 @@ typedef struct _cef_life_span_handler_t {
   ///     CefJSDialogHandler::OnBeforeUnloadDialog()).
   /// 4.  User approves the close. 5.  JavaScript 'onunload' handler executes.
   /// 6.  Application's do_close() handler is called. Application will:
-  ///     A. Set a flag to indicate that the next close attempt will be allowed.
+  ///     A. Set a flag to indicate that the next top-level window close attempt
+  ///        will be allowed.
   ///     B. Return false.
-  /// 7.  CEF sends an close notification to the application's top-level window.
+  /// 7.  CEF sends a close notification to the application's top-level window
+  ///     (because DoClose() returned false).
   /// 8.  Application's top-level window receives the close notification and
-  ///     allows the window to close based on the flag from #6B.
-  /// 9.  Application's top-level window is destroyed. 10. Application's
-  /// on_before_close() handler is called and the browser object
+  ///     allows the window to close based on the flag from #6A.
+  /// 9.  Application's top-level window is destroyed, triggering destruction
+  ///     of the child browser window.
+  /// 10. Application's on_before_close() handler is called and the browser
+  /// object
   ///     is destroyed.
   /// 11. Application exits by calling cef_quit_message_loop() if no other
   /// browsers

include/cef_api_hash.h

@@ -42,13 +42,13 @@
 // way that may cause binary incompatibility with other builds. The universal
 // hash value will change if any platform is affected whereas the platform hash
 // values will change only if that particular platform is affected.
-#define CEF_API_HASH_UNIVERSAL "9717d7221d63adfd79ee52e2a31c9ac7acdd6d50"
+#define CEF_API_HASH_UNIVERSAL "676af077d6826353caf40425f5f2bae1262347ea"
 #if defined(OS_WIN)
-#define CEF_API_HASH_PLATFORM "072a4fe61a512f21fd0d664495902fca6ec2193b"
+#define CEF_API_HASH_PLATFORM "51848171cdea10858c4e0fca0f7099b0fdc759f9"
 #elif defined(OS_MAC)
-#define CEF_API_HASH_PLATFORM "ee7f0e9247add8df0827d02da32559e38e8079d0"
+#define CEF_API_HASH_PLATFORM "8cc826c5f5fe97c275dfa3b9c020470678a5d2fd"
 #elif defined(OS_LINUX)
-#define CEF_API_HASH_PLATFORM "88996e58ee062016efd054bfbafd03dd3daa99ed"
+#define CEF_API_HASH_PLATFORM "0aec2348de1bf14fafa7a23baa0df942d342d409"
 #endif
 
 #ifdef __cplusplus

include/cef_browser.h

@@ -331,30 +331,63 @@ class CefBrowserHost : public virtual CefBaseRefCounted {
   virtual CefRefPtr<CefBrowser> GetBrowser() = 0;
 
   ///
-  /// Request that the browser close. The JavaScript 'onbeforeunload' event will
-  /// be fired. If |force_close| is false the event handler, if any, will be
-  /// allowed to prompt the user and the user can optionally cancel the close.
-  /// If |force_close| is true the prompt will not be displayed and the close
-  /// will proceed. Results in a call to CefLifeSpanHandler::DoClose() if the
-  /// event handler allows the close or if |force_close| is true. See
-  /// CefLifeSpanHandler::DoClose() documentation for additional usage
-  /// information.
+  /// Request that the browser close. Closing a browser is a multi-stage process
+  /// that may complete either synchronously or asynchronously, and involves
+  /// callbacks such as CefLifeSpanHandler::DoClose (Alloy style only),
+  /// CefLifeSpanHandler::OnBeforeClose, and a top-level window close handler
+  /// such as CefWindowDelegate::CanClose (or platform-specific equivalent). In
+  /// some cases a close request may be delayed or canceled by the user. Using
+  /// TryCloseBrowser() instead of CloseBrowser() is recommended for most use
+  /// cases. See CefLifeSpanHandler::DoClose() documentation for detailed usage
+  /// and examples.
+  ///
+  /// If |force_close| is false then JavaScript unload handlers, if any, may be
+  /// fired and the close may be delayed or canceled by the user. If
+  /// |force_close| is true then the user will not be prompted and the close
+  /// will proceed immediately (possibly asynchronously). If browser close is
+  /// delayed and not canceled the default behavior is to call the top-level
+  /// window close handler once the browser is ready to be closed. This default
+  /// behavior can be changed for Alloy style browsers by implementing
+  /// CefLifeSpanHandler::DoClose(). IsReadyToBeClosed() can be used to detect
+  /// mandatory browser close events when customizing close behavior on the
+  /// browser process UI thread.
   ///
   /*--cef()--*/
   virtual void CloseBrowser(bool force_close) = 0;
 
   ///
-  /// Helper for closing a browser. Call this method from the top-level window
-  /// close handler (if any). Internally this calls CloseBrowser(false) if the
-  /// close has not yet been initiated. This method returns false while the
-  /// close is pending and true after the close has completed. See
-  /// CloseBrowser() and CefLifeSpanHandler::DoClose() documentation for
-  /// additional usage information. This method must be called on the browser
-  /// process UI thread.
+  /// Helper for closing a browser. This is similar in behavior to
+  /// CLoseBrowser(false) but returns a boolean to reflect the immediate close
+  /// status. Call this method from a top-level window close handler such as
+  /// CefWindowDelegate::CanClose (or platform-specific equivalent) to request
+  /// that the browser close, and return the result to indicate if the window
+  /// close should proceed. Returns false if the close will be delayed
+  /// (JavaScript unload handlers triggered but still pending) or true if the
+  /// close will proceed immediately (possibly asynchronously). See
+  /// CloseBrowser() documentation for additional usage information. This method
+  /// must be called on the browser process UI thread.
   ///
   /*--cef()--*/
   virtual bool TryCloseBrowser() = 0;
 
+  ///
+  /// Returns true if the browser is ready to be closed, meaning that the close
+  /// has already been initiated and that JavaScript unload handlers have
+  /// already executed or should be ignored. This can be used from a top-level
+  /// window close handler such as CefWindowDelegate::CanClose (or
+  /// platform-specific equivalent) to distringuish between potentially
+  /// cancelable browser close events (like the user clicking the top-level
+  /// window close button before browser close has started) and mandatory
+  /// browser close events (like JavaScript `window.close()` or after browser
+  /// close has started in response to [Try]CloseBrowser()). Not completing the
+  /// browser close for mandatory close events (when this method returns true)
+  /// will leave the browser in a partially closed state that interferes with
+  /// proper functioning. See CloseBrowser() documentation for additional usage
+  /// information. This method must be called on the browser process UI thread.
+  ///
+  /*--cef()--*/
+  virtual bool IsReadyToBeClosed() = 0;
+
   ///
   /// Set whether the browser is focused.
   ///

include/cef_life_span_handler.h

@@ -131,34 +131,44 @@ class CefLifeSpanHandler : public virtual CefBaseRefCounted {
   virtual void OnAfterCreated(CefRefPtr<CefBrowser> browser) {}
 
   ///
-  /// Called when a browser has received a request to close. This may result
-  /// directly from a call to CefBrowserHost::*CloseBrowser() or indirectly if
-  /// the browser is parented to a top-level window created by CEF and the user
-  /// attempts to close that window (by clicking the 'X', for example). The
-  /// DoClose() method will be called after the JavaScript 'onunload' event has
-  /// been fired.
+  /// Called when an Alloy style browser is ready to be closed, meaning that the
+  /// close has already been initiated and that JavaScript unload handlers have
+  /// already executed or should be ignored. This may result directly from a
+  /// call to CefBrowserHost::[Try]CloseBrowser() or indirectly if the browser's
+  /// top-level parent window was created by CEF and the user attempts to
+  /// close that window (by clicking the 'X', for example). DoClose() will not
+  /// be called if the browser's host window/view has already been destroyed
+  /// (via parent window/view hierarchy tear-down, for example), as it is no
+  /// longer possible to customize the close behavior at that point.
   ///
-  /// An application should handle top-level owner window close notifications by
-  /// calling CefBrowserHost::TryCloseBrowser() or
+  /// An application should handle top-level parent window close notifications
+  /// by calling CefBrowserHost::TryCloseBrowser() or
   /// CefBrowserHost::CloseBrowser(false) instead of allowing the window to
   /// close immediately (see the examples below). This gives CEF an opportunity
-  /// to process the 'onbeforeunload' event and optionally cancel the close
+  /// to process JavaScript unload handlers and optionally cancel the close
   /// before DoClose() is called.
   ///
-  /// When windowed rendering is enabled CEF will internally create a window or
-  /// view to host the browser. In that case returning false from DoClose() will
-  /// send the standard close notification to the browser's top-level owner
-  /// window (e.g. WM_CLOSE on Windows, performClose: on OS X, "delete_event" on
-  /// Linux or CefWindowDelegate::CanClose() callback from Views). If the
-  /// browser's host window/view has already been destroyed (via view hierarchy
-  /// tear-down, for example) then DoClose() will not be called for that browser
-  /// since is no longer possible to cancel the close.
+  /// When windowed rendering is enabled CEF will create an internal child
+  /// window/view to host the browser. In that case returning false from
+  /// DoClose() will send the standard close notification to the browser's
+  /// top-level parent window (e.g. WM_CLOSE on Windows, performClose: on OS X,
+  /// "delete_event" on Linux or CefWindowDelegate::CanClose() callback from
+  /// Views).
   ///
-  /// When windowed rendering is disabled returning false from DoClose() will
-  /// cause the browser object to be destroyed immediately.
+  /// When windowed rendering is disabled there is no internal window/view
+  /// and returning false from DoClose() will cause the browser object to be
+  /// destroyed immediately.
   ///
-  /// If the browser's top-level owner window requires a non-standard close
+  /// If the browser's top-level parent window requires a non-standard close
   /// notification then send that notification from DoClose() and return true.
+  /// You are still required to complete the browser close as soon as possible
+  /// (either by calling [Try]CloseBrowser() or by proceeding with window/view
+  /// hierarchy tear-down), otherwise the browser will be left in a partially
+  /// closed state that interferes with proper functioning. Top-level windows
+  /// created on the browser process UI thread can alternately call
+  /// CefBrowserHost::IsReadyToBeClosed() in the close handler to check close
+  /// status instead of relying on custom DoClose() handling. See documentation
+  /// on that method for additional details.
   ///
   /// The CefLifeSpanHandler::OnBeforeClose() method will be called after
   /// DoClose() (if DoClose() is called) and immediately before the browser
@@ -174,7 +184,7 @@ class CefLifeSpanHandler : public virtual CefBaseRefCounted {
   /// 1.  User clicks the window close button which sends a close notification
   ///     to the application's top-level window.
   /// 2.  Application's top-level window receives the close notification and
-  ///     calls TryCloseBrowser() (which internally calls CloseBrowser(false)).
+  ///     calls TryCloseBrowser() (similar to calling CloseBrowser(false)).
   ///     TryCloseBrowser() returns false so the client cancels the window
   ///     close.
   /// 3.  JavaScript 'onbeforeunload' handler executes and shows the close
@@ -182,15 +192,18 @@ class CefLifeSpanHandler : public virtual CefBaseRefCounted {
   ///     CefJSDialogHandler::OnBeforeUnloadDialog()).
   /// 4.  User approves the close.
   /// 5.  JavaScript 'onunload' handler executes.
-  /// 6.  CEF sends a close notification to the application's top-level window
-  ///     (because DoClose() returned false by default).
-  /// 7.  Application's top-level window receives the close notification and
+  /// 6.  Application's DoClose() handler is called and returns false by
+  ///     default.
+  /// 7.  CEF sends a close notification to the application's top-level window
+  ///     (because DoClose() returned false).
+  /// 8.  Application's top-level window receives the close notification and
   ///     calls TryCloseBrowser(). TryCloseBrowser() returns true so the client
   ///     allows the window close.
-  /// 8.  Application's top-level window is destroyed.
-  /// 9.  Application's OnBeforeClose() handler is called and the browser object
+  /// 9.  Application's top-level window is destroyed, triggering destruction
+  ///     of the child browser window.
+  /// 10. Application's OnBeforeClose() handler is called and the browser object
   ///     is destroyed.
-  /// 10. Application exits by calling CefQuitMessageLoop() if no other browsers
+  /// 11. Application exits by calling CefQuitMessageLoop() if no other browsers
   ///     exist.
   ///
   /// Example 2: Using CefBrowserHost::CloseBrowser(false) and implementing the
@@ -208,12 +221,15 @@ class CefLifeSpanHandler : public virtual CefBaseRefCounted {
   /// 4.  User approves the close.
   /// 5.  JavaScript 'onunload' handler executes.
   /// 6.  Application's DoClose() handler is called. Application will:
-  ///     A. Set a flag to indicate that the next close attempt will be allowed.
+  ///     A. Set a flag to indicate that the next top-level window close attempt
+  ///        will be allowed.
   ///     B. Return false.
-  /// 7.  CEF sends an close notification to the application's top-level window.
+  /// 7.  CEF sends a close notification to the application's top-level window
+  ///     (because DoClose() returned false).
   /// 8.  Application's top-level window receives the close notification and
-  ///     allows the window to close based on the flag from #6B.
-  /// 9.  Application's top-level window is destroyed.
+  ///     allows the window to close based on the flag from #6A.
+  /// 9.  Application's top-level window is destroyed, triggering destruction
+  ///     of the child browser window.
   /// 10. Application's OnBeforeClose() handler is called and the browser object
   ///     is destroyed.
   /// 11. Application exits by calling CefQuitMessageLoop() if no other browsers

libcef/browser/browser_host_base.cc

@@ -452,6 +452,20 @@ bool CefBrowserHostBase::HasView() {
   return is_views_hosted_;
 }
 
+bool CefBrowserHostBase::IsReadyToBeClosed() {
+  if (!CEF_CURRENTLY_ON_UIT()) {
+    DCHECK(false) << "called on invalid thread";
+    return false;
+  }
+
+  if (auto web_contents = GetWebContents()) {
+    return static_cast<content::RenderFrameHostImpl*>(
+               web_contents->GetPrimaryMainFrame())
+        ->IsPageReadyToBeClosed();
+  }
+  return true;
+}
+
 void CefBrowserHostBase::SetFocus(bool focus) {
   if (!CEF_CURRENTLY_ON_UIT()) {
     CEF_POST_TASK(CEF_UIT,

libcef/browser/browser_host_base.h

@@ -218,6 +218,7 @@ class CefBrowserHostBase : public CefBrowserHost,
   double GetZoomLevel() override;
   void SetZoomLevel(double zoomLevel) override;
   bool HasView() override;
+  bool IsReadyToBeClosed() override;
   void SetFocus(bool focus) override;
   void RunFileDialog(FileDialogMode mode,
                      const CefString& title,

libcef/browser/browser_platform_delegate.cc

@@ -63,6 +63,10 @@ class PopupWindowDelegate : public CefWindowDelegate {
     return true;
   }
 
+  cef_runtime_style_t GetWindowRuntimeStyle() override {
+    return browser_view_->GetRuntimeStyle();
+  }
+
  private:
   CefRefPtr<CefBrowserView> browser_view_;
 
@@ -195,8 +199,9 @@ void CefBrowserPlatformDelegate::PopupWebContentsCreated(
   }
 
   CefRefPtr<CefBrowserViewDelegate> new_delegate;
-
   CefRefPtr<CefBrowserViewDelegate> opener_delegate;
+  cef_runtime_style_t opener_runtime_style = CEF_RUNTIME_STYLE_DEFAULT;
+
   auto browser_view = GetBrowserView();
   if (browser_view) {
     // When |this| (the popup opener) is Views-hosted use the current delegate.
@@ -212,12 +217,22 @@ void CefBrowserPlatformDelegate::PopupWebContentsCreated(
         browser_view, settings, client, is_devtools);
   }
 
+  if (browser_view) {
+    opener_runtime_style = browser_view->GetRuntimeStyle();
+  } else if (opener_delegate) {
+    opener_runtime_style = opener_delegate->GetBrowserRuntimeStyle();
+  }
+
   // Create a new BrowserView for the popup.
   CefRefPtr<CefBrowserViewImpl> new_browser_view =
-      CefBrowserViewImpl::CreateForPopup(settings, new_delegate, is_devtools);
+      CefBrowserViewImpl::CreateForPopup(settings, new_delegate, is_devtools,
+                                         opener_runtime_style);
 
   // Associate the PlatformDelegate with the new BrowserView.
   new_platform_delegate->SetBrowserView(new_browser_view);
+
+  // Keep the BrowserView alive until PopupBrowserCreated() is called.
+  new_browser_view->AddRef();
 }
 
 void CefBrowserPlatformDelegate::PopupBrowserCreated(
@@ -255,6 +270,9 @@ void CefBrowserPlatformDelegate::PopupBrowserCreated(
     CefWindow::CreateTopLevelWindow(
         new PopupWindowDelegate(new_browser_view.get()));
   }
+
+  // Release the reference added in PopupWebContentsCreated().
+  new_browser_view->Release();
 }
 
 CefRefPtr<CefBrowserViewDelegate>

libcef/browser/chrome/chrome_browser_host_impl.cc

@@ -165,14 +165,47 @@ void ChromeBrowserHostImpl::OnSetFocus(cef_focus_source_t source) {
 }
 
 void ChromeBrowserHostImpl::CloseBrowser(bool force_close) {
+  if (!CEF_CURRENTLY_ON_UIT()) {
+    CEF_POST_TASK(CEF_UIT, base::BindOnce(&ChromeBrowserHostImpl::CloseBrowser,
+                                          this, force_close));
+    return;
+  }
+
+  if (!force_close) {
+    TryCloseBrowser();
+    return;
+  }
+
   // Always do this asynchronously because TabStripModel is not re-entrant.
-  CEF_POST_TASK(CEF_UIT, base::BindOnce(&ChromeBrowserHostImpl::DoCloseBrowser,
-                                        this, force_close));
+  CEF_POST_TASK(CEF_UIT,
+                base::BindOnce(&ChromeBrowserHostImpl::DoCloseBrowser, this));
 }
 
 bool ChromeBrowserHostImpl::TryCloseBrowser() {
-  // TODO(chrome): Handle the case where the browser may not close immediately.
-  CloseBrowser(true);
+  if (!CEF_CURRENTLY_ON_UIT()) {
+    DCHECK(false) << "called on invalid thread";
+    return false;
+  }
+
+  if (auto* web_contents = GetWebContents()) {
+    // This check works as follows:
+    // 1. Returns false if the main frame is ready to close
+    //    (IsPageReadyToBeClosed returns true).
+    // 2. Otherwise returns true if any frame in the frame tree needs to run
+    //    beforeunload or unload-time event handlers.
+    // 3. Otherwise returns false.
+    if (web_contents->NeedToFireBeforeUnloadOrUnloadEvents()) {
+      // Will result in a call to Browser::BeforeUnloadFired and, if the close
+      // isn't canceled, Browser::CloseContents which indirectly calls
+      // TabStripModel::CloseWebContentsAt (similar to DoCloseBrowser but
+      // without CLOSE_USER_GESTURE). Additional calls to DispatchBeforeUnload
+      // while the unload is pending will be ignored.
+      web_contents->DispatchBeforeUnload(/*auto_cancel=*/false);
+      return false;
+    }
+  }
+
+  CloseBrowser(/*force_close=*/true);
   return true;
 }
 
@@ -551,7 +584,7 @@ void ChromeBrowserHostImpl::DestroyBrowser() {
   // WebContents first. See comments on CefBrowserHostBase::DestroyBrowser.
   if (GetWebContents()) {
     // Triggers a call to OnWebContentsDestroyed.
-    DoCloseBrowser(/*force_close=*/true);
+    DoCloseBrowser();
     DCHECK(!GetWebContents());
   }
 
@@ -565,15 +598,13 @@ void ChromeBrowserHostImpl::DestroyBrowser() {
   CefBrowserHostBase::DestroyBrowser();
 }
 
-void ChromeBrowserHostImpl::DoCloseBrowser(bool force_close) {
+void ChromeBrowserHostImpl::DoCloseBrowser() {
   CEF_REQUIRE_UIT();
   if (browser_) {
     // Like chrome::CloseTab() but specifying the WebContents.
     const int tab_index = GetCurrentTabIndex();
     if (tab_index != TabStripModel::kNoTab) {
       // This will trigger destruction of the Browser and WebContents.
-      // TODO(chrome): Handle the case where this method returns false,
-      // indicating that the contents were not closed immediately.
       browser_->tab_strip_model()->CloseWebContentsAt(
           tab_index, TabCloseTypes::CLOSE_CREATE_HISTORICAL_TAB |
                          TabCloseTypes::CLOSE_USER_GESTURE);

libcef/browser/chrome/chrome_browser_host_impl.h

@@ -169,7 +169,7 @@ class ChromeBrowserHostImpl : public CefBrowserHostBase {
   bool WillBeDestroyed() const override;
   void DestroyBrowser() override;
 
-  void DoCloseBrowser(bool force_close);
+  void DoCloseBrowser();
 
   // Returns the current tab index for the associated WebContents, or
   // TabStripModel::kNoTab if not found.

libcef/browser/chrome/chrome_browser_main_extra_parts_cef.cc

@@ -17,6 +17,7 @@
 
 #if BUILDFLAG(IS_LINUX)
 #include "base/linux_util.h"
+#include "cef/libcef/browser/printing/print_dialog_linux.h"
 #endif
 
 #if BUILDFLAG(IS_WIN)
@@ -83,4 +84,11 @@ void ChromeBrowserMainExtraPartsCef::ToolkitInitialized() {
   // Override the default Chrome client.
   SetConstrainedWindowViewsClient(CreateAlloyConstrainedWindowViewsClient(
       CreateChromeConstrainedWindowViewsClient()));
+
+#if BUILDFLAG(IS_LINUX)
+  auto printing_delegate = new CefPrintingContextLinuxDelegate();
+  auto default_delegate =
+      ui::PrintingContextLinuxDelegate::SetInstance(printing_delegate);
+  printing_delegate->SetDefaultDelegate(default_delegate);
+#endif  // BUILDFLAG(IS_LINUX)
 }

libcef/browser/chrome/views/browser_platform_delegate_chrome_views.cc

@@ -24,7 +24,8 @@ void CefBrowserPlatformDelegateChromeViews::SetBrowserView(
     CefRefPtr<CefBrowserView> browser_view) {
   DCHECK(!browser_view_);
   DCHECK(browser_view);
-  browser_view_ = static_cast<CefBrowserViewImpl*>(browser_view.get());
+  browser_view_ =
+      static_cast<CefBrowserViewImpl*>(browser_view.get())->GetWeakPtr();
 }
 
 void CefBrowserPlatformDelegateChromeViews::WebContentsCreated(
@@ -37,7 +38,10 @@ void CefBrowserPlatformDelegateChromeViews::WebContentsCreated(
 void CefBrowserPlatformDelegateChromeViews::WebContentsDestroyed(
     content::WebContents* web_contents) {
   CefBrowserPlatformDelegateChrome::WebContentsDestroyed(web_contents);
-  browser_view_->WebContentsDestroyed(web_contents);
+  // |browser_view_| may be destroyed before this callback arrives.
+  if (browser_view_) {
+    browser_view_->WebContentsDestroyed(web_contents);
+  }
 }
 
 void CefBrowserPlatformDelegateChromeViews::BrowserCreated(
@@ -48,7 +52,7 @@ void CefBrowserPlatformDelegateChromeViews::BrowserCreated(
 
 void CefBrowserPlatformDelegateChromeViews::NotifyBrowserCreated() {
   if (auto delegate = browser_view_->delegate()) {
-    delegate->OnBrowserCreated(browser_view_, browser_.get());
+    delegate->OnBrowserCreated(browser_view_.get(), browser_.get());
 
     // DevTools windows hide the notification bubble by default. However, we
     // don't currently have the ability to intercept WebContents creation via
@@ -75,8 +79,9 @@ void CefBrowserPlatformDelegateChromeViews::NotifyBrowserCreated() {
 }
 
 void CefBrowserPlatformDelegateChromeViews::NotifyBrowserDestroyed() {
-  if (browser_view_->delegate()) {
-    browser_view_->delegate()->OnBrowserDestroyed(browser_view_,
+  // |browser_view_| may be destroyed before this callback arrives.
+  if (browser_view_ && browser_view_->delegate()) {
+    browser_view_->delegate()->OnBrowserDestroyed(browser_view_.get(),
                                                   browser_.get());
   }
 }
@@ -84,7 +89,11 @@ void CefBrowserPlatformDelegateChromeViews::NotifyBrowserDestroyed() {
 void CefBrowserPlatformDelegateChromeViews::BrowserDestroyed(
     CefBrowserHostBase* browser) {
   CefBrowserPlatformDelegateChrome::BrowserDestroyed(browser);
-  browser_view_->BrowserDestroyed(browser);
+  // |browser_view_| may be destroyed before this callback arrives.
+  if (browser_view_) {
+    browser_view_->BrowserDestroyed(browser);
+  }
+  browser_view_ = nullptr;
 }
 
 void CefBrowserPlatformDelegateChromeViews::CloseHostWindow() {
@@ -100,7 +109,7 @@ CefWindowHandle CefBrowserPlatformDelegateChromeViews::GetHostWindowHandle()
 }
 
 views::Widget* CefBrowserPlatformDelegateChromeViews::GetWindowWidget() const {
-  if (browser_view_->root_view()) {
+  if (browser_view_ && browser_view_->root_view()) {
     return browser_view_->root_view()->GetWidget();
   }
   return nullptr;

libcef/browser/chrome/views/browser_platform_delegate_chrome_views.h

@@ -5,6 +5,7 @@
 #ifndef CEF_LIBCEF_BROWSER_CHROME_VIEWS_BROWSER_PLATFORM_DELEGATE_CHROME_VIEWS_H_
 #define CEF_LIBCEF_BROWSER_CHROME_VIEWS_BROWSER_PLATFORM_DELEGATE_CHROME_VIEWS_H_
 
+#include "base/memory/weak_ptr.h"
 #include "cef/libcef/browser/chrome/browser_platform_delegate_chrome.h"
 #include "cef/libcef/browser/views/browser_view_impl.h"
 
@@ -33,12 +34,17 @@ class CefBrowserPlatformDelegateChromeViews
   void SetBrowserView(CefRefPtr<CefBrowserView> browser_view) override;
   bool IsViewsHosted() const override;
 
-  CefRefPtr<CefBrowserViewImpl> browser_view() const { return browser_view_; }
+  CefBrowserViewImpl* browser_view() const { return browser_view_.get(); }
 
  private:
   CefWindowImpl* GetWindowImpl() const;
 
-  CefRefPtr<CefBrowserViewImpl> browser_view_;
+  // Holding a weak reference here because we want the CefBrowserViewImpl to be
+  // destroyed first if all references are released by the client.
+  // CefBrowserViewImpl destruction will then trigger destruction of any
+  // associated CefBrowserHostBase (which owns this CefBrowserPlatformDelegate
+  // object).
+  base::WeakPtr<CefBrowserViewImpl> browser_view_;
 };
 
 #endif  // CEF_LIBCEF_BROWSER_CHROME_VIEWS_BROWSER_PLATFORM_DELEGATE_CHROME_VIEWS_H_

libcef/browser/chrome/views/chrome_browser_view.cc

@@ -11,6 +11,13 @@ ChromeBrowserView::ChromeBrowserView(CefBrowserViewImpl* cef_browser_view)
     : ParentClass(cef_browser_view->delegate()),
       cef_browser_view_(cef_browser_view) {}
 
+ChromeBrowserView::~ChromeBrowserView() {
+  if (cef_toolbar_) {
+    WillDestroyToolbar();
+    cef_toolbar_ = nullptr;
+  }
+}
+
 void ChromeBrowserView::InitBrowser(std::unique_ptr<Browser> browser) {
   DCHECK(!web_view_);
 

libcef/browser/chrome/views/chrome_browser_view.h

@@ -30,6 +30,7 @@ class ChromeBrowserView
 
   // |cef_browser_view| is non-nullptr and will outlive this object.
   explicit ChromeBrowserView(CefBrowserViewImpl* cef_browser_view);
+  ~ChromeBrowserView() override;
 
   ChromeBrowserView(const ChromeBrowserView&) = delete;
   ChromeBrowserView& operator=(const ChromeBrowserView&) = delete;

libcef/browser/main_runner.cc

@@ -449,9 +449,6 @@ void CefMainRunner::StartShutdownOnUIThread(
   content::BrowserTaskExecutor::RunAllPendingTasksOnThreadForTesting(
       content::BrowserThread::IO);
 
-  static_cast<content::ContentMainRunnerImpl*>(main_runner_.get())
-      ->ShutdownOnUIThread();
-
   std::move(shutdown_on_ui_thread).Run();
   BeforeUIThreadShutdown();
 }
@@ -462,6 +459,9 @@ void CefMainRunner::FinishShutdownOnUIThread() {
     // It is safe to call multiple times.
     ChromeProcessSingleton::DeleteInstance();
   }
+
+   static_cast<content::ContentMainRunnerImpl*>(main_runner_.get())
+      ->ShutdownOnUIThread();
 }
 
 void CefMainRunner::BeforeUIThreadInitialize() {

libcef/browser/views/browser_platform_delegate_views.cc

@@ -27,7 +27,8 @@ void CefBrowserPlatformDelegateViews::SetBrowserView(
     CefRefPtr<CefBrowserView> browser_view) {
   DCHECK(!browser_view_);
   DCHECK(browser_view);
-  browser_view_ = static_cast<CefBrowserViewImpl*>(browser_view.get());
+  browser_view_ =
+      static_cast<CefBrowserViewImpl*>(browser_view.get())->GetWeakPtr();
 }
 
 void CefBrowserPlatformDelegateViews::WebContentsCreated(
@@ -41,7 +42,10 @@ void CefBrowserPlatformDelegateViews::WebContentsCreated(
 void CefBrowserPlatformDelegateViews::WebContentsDestroyed(
     content::WebContents* web_contents) {
   CefBrowserPlatformDelegateAlloy::WebContentsDestroyed(web_contents);
-  browser_view_->WebContentsCreated(web_contents);
+  // |browser_view_| may be destroyed before this callback arrives.
+  if (browser_view_) {
+    browser_view_->WebContentsDestroyed(web_contents);
+  }
   native_delegate_->WebContentsDestroyed(web_contents);
 }
 
@@ -57,15 +61,16 @@ void CefBrowserPlatformDelegateViews::NotifyBrowserCreated() {
   DCHECK(browser_view_);
   DCHECK(browser_);
   if (browser_view_->delegate()) {
-    browser_view_->delegate()->OnBrowserCreated(browser_view_, browser_.get());
+    browser_view_->delegate()->OnBrowserCreated(browser_view_.get(),
+                                                browser_.get());
   }
 }
 
 void CefBrowserPlatformDelegateViews::NotifyBrowserDestroyed() {
-  DCHECK(browser_view_);
   DCHECK(browser_);
-  if (browser_view_->delegate()) {
-    browser_view_->delegate()->OnBrowserDestroyed(browser_view_,
+  // |browser_view_| may be destroyed before this callback arrives.
+  if (browser_view_ && browser_view_->delegate()) {
+    browser_view_->delegate()->OnBrowserDestroyed(browser_view_.get(),
                                                   browser_.get());
   }
 }
@@ -74,7 +79,10 @@ void CefBrowserPlatformDelegateViews::BrowserDestroyed(
     CefBrowserHostBase* browser) {
   CefBrowserPlatformDelegateAlloy::BrowserDestroyed(browser);
 
-  browser_view_->BrowserDestroyed(browser);
+  // |browser_view_| may be destroyed before this callback arrives.
+  if (browser_view_) {
+    browser_view_->BrowserDestroyed(browser);
+  }
   browser_view_ = nullptr;
   native_delegate_->BrowserDestroyed(browser);
 }

libcef/browser/views/browser_platform_delegate_views.h

@@ -5,6 +5,7 @@
 #ifndef CEF_LIBCEF_BROWSER_VIEWS_BROWSER_PLATFORM_DELEGATE_VIEWS_H_
 #define CEF_LIBCEF_BROWSER_VIEWS_BROWSER_PLATFORM_DELEGATE_VIEWS_H_
 
+#include "base/memory/weak_ptr.h"
 #include "cef/libcef/browser/alloy/browser_platform_delegate_alloy.h"
 #include "cef/libcef/browser/native/browser_platform_delegate_native.h"
 #include "cef/libcef/browser/views/browser_view_impl.h"
@@ -65,7 +66,13 @@ class CefBrowserPlatformDelegateViews
 
  private:
   std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate_;
-  CefRefPtr<CefBrowserViewImpl> browser_view_;
+
+  // Holding a weak reference here because we want the CefBrowserViewImpl to be
+  // destroyed first if all references are released by the client.
+  // CefBrowserViewImpl destruction will then trigger destruction of any
+  // associated CefBrowserHostBase (which owns this CefBrowserPlatformDelegate
+  // object).
+  base::WeakPtr<CefBrowserViewImpl> browser_view_;
 };
 
 #endif  // CEF_LIBCEF_BROWSER_VIEWS_BROWSER_PLATFORM_DELEGATE_VIEWS_H_

libcef/browser/views/browser_view_impl.cc

@@ -35,30 +35,39 @@ std::optional<cef_gesture_command_t> GetGestureCommand(
   return std::nullopt;
 }
 
-bool ComputeAlloyStyle(CefBrowserViewDelegate* cef_delegate,
-                       bool is_devtools_popup) {
-  // Alloy style is not supported with Chrome DevTools popups.
-  const bool supports_alloy_style = !is_devtools_popup;
-  const auto default_style = CEF_RUNTIME_STYLE_CHROME;
-
-  auto result_style = default_style;
-
-  if (cef_delegate) {
-    auto requested_style = cef_delegate->GetBrowserRuntimeStyle();
-    if (requested_style == CEF_RUNTIME_STYLE_ALLOY) {
-      if (supports_alloy_style) {
-        result_style = requested_style;
-      } else {
-        LOG(ERROR) << "GetBrowserRuntimeStyle() requested Alloy style; only "
-                      "Chrome style is supported";
-      }
-    } else if (requested_style == CEF_RUNTIME_STYLE_CHROME) {
-      // Chrome style is always supported.
-      result_style = requested_style;
+bool ComputeAlloyStyle(
+    CefBrowserViewDelegate* cef_delegate,
+    bool is_devtools_popup,
+    std::optional<cef_runtime_style_t> opener_runtime_style) {
+  if (is_devtools_popup) {
+    // Alloy style is not supported with Chrome DevTools popups.
+    if (cef_delegate &&
+        cef_delegate->GetBrowserRuntimeStyle() == CEF_RUNTIME_STYLE_ALLOY) {
+      LOG(ERROR) << "GetBrowserRuntimeStyle() requested Alloy style; only "
+                    "Chrome style is supported for DevTools popups";
     }
+    return false;
   }
 
-  return result_style == CEF_RUNTIME_STYLE_ALLOY;
+  if (opener_runtime_style) {
+    // Popup style must match the opener style.
+    const bool opener_alloy_style =
+        *opener_runtime_style == CEF_RUNTIME_STYLE_ALLOY;
+    if (cef_delegate) {
+      const auto requested_style = cef_delegate->GetBrowserRuntimeStyle();
+      if (requested_style != CEF_RUNTIME_STYLE_DEFAULT &&
+          requested_style != (opener_alloy_style ? CEF_RUNTIME_STYLE_ALLOY
+                                                 : CEF_RUNTIME_STYLE_CHROME)) {
+        LOG(ERROR)
+            << "GetBrowserRuntimeStyle() for popups must match opener style";
+      }
+    }
+    return opener_alloy_style;
+  }
+
+  // Chrome style is the default unless Alloy is specifically requested.
+  return cef_delegate &&
+         cef_delegate->GetBrowserRuntimeStyle() == CEF_RUNTIME_STYLE_ALLOY;
 }
 
 }  // namespace
@@ -111,7 +120,8 @@ CefRefPtr<CefBrowserViewImpl> CefBrowserViewImpl::Create(
   }
 
   CefRefPtr<CefBrowserViewImpl> browser_view =
-      new CefBrowserViewImpl(delegate, /*is_devtools_popup=*/false);
+      new CefBrowserViewImpl(delegate, /*is_devtools_popup=*/false,
+                             /*opener_runtime_style=*/std::nullopt);
   browser_view->SetPendingBrowserCreateParams(
       window_info, client, url, settings, extra_info, request_context);
   browser_view->Initialize();
@@ -123,16 +133,38 @@ CefRefPtr<CefBrowserViewImpl> CefBrowserViewImpl::Create(
 CefRefPtr<CefBrowserViewImpl> CefBrowserViewImpl::CreateForPopup(
     const CefBrowserSettings& settings,
     CefRefPtr<CefBrowserViewDelegate> delegate,
-    bool is_devtools) {
+    bool is_devtools,
+    cef_runtime_style_t opener_runtime_style) {
   CEF_REQUIRE_UIT_RETURN(nullptr);
 
   CefRefPtr<CefBrowserViewImpl> browser_view =
-      new CefBrowserViewImpl(delegate, is_devtools);
+      new CefBrowserViewImpl(delegate, is_devtools, opener_runtime_style);
   browser_view->Initialize();
   browser_view->SetDefaults(settings);
   return browser_view;
 }
 
+CefBrowserViewImpl::~CefBrowserViewImpl() {
+  // We want no further callbacks to this object.
+  weak_ptr_factory_.InvalidateWeakPtrs();
+
+  // |browser_| may exist here if the BrowserView was removed from the Views
+  // hierarchy prior to tear-down and the last BrowserView reference was
+  // released. In that case DisassociateFromWidget() will be called when the
+  // BrowserView is removed from the Window but Detach() will not be called
+  // because the BrowserView was not destroyed via the Views hierarchy
+  // tear-down.
+  DCHECK(!cef_widget_);
+  if (browser_ && !browser_->WillBeDestroyed()) {
+    // With Alloy style |browser_| will disappear when WindowDestroyed()
+    // indirectly calls BrowserDestroyed() so keep a reference.
+    CefRefPtr<CefBrowserHostBase> browser = browser_;
+
+    // Force the browser to be destroyed.
+    browser->WindowDestroyed();
+  }
+}
+
 void CefBrowserViewImpl::WebContentsCreated(
     content::WebContents* web_contents) {
   if (web_view()) {
@@ -269,8 +301,8 @@ void CefBrowserViewImpl::AddedToWidget() {
   CefWidget* cef_widget = CefWidget::GetForWidget(widget);
   DCHECK(cef_widget);
 
-  if (!browser_) {
-    if (cef_widget->IsAlloyStyle() && !is_alloy_style_) {
+  if (!browser_ && !is_alloy_style_) {
+    if (cef_widget->IsAlloyStyle()) {
       LOG(ERROR) << "Cannot add Chrome style BrowserView to Alloy style Window";
       return;
     }
@@ -337,9 +369,12 @@ bool CefBrowserViewImpl::OnGestureEvent(ui::GestureEvent* event) {
 
 CefBrowserViewImpl::CefBrowserViewImpl(
     CefRefPtr<CefBrowserViewDelegate> delegate,
-    bool is_devtools_popup)
+    bool is_devtools_popup,
+    std::optional<cef_runtime_style_t> opener_runtime_style)
     : ParentClass(delegate),
-      is_alloy_style_(ComputeAlloyStyle(delegate.get(), is_devtools_popup)),
+      is_alloy_style_(ComputeAlloyStyle(delegate.get(),
+                                        is_devtools_popup,
+                                        opener_runtime_style)),
       weak_ptr_factory_(this) {}
 
 void CefBrowserViewImpl::SetPendingBrowserCreateParams(

libcef/browser/views/browser_view_impl.h

@@ -6,6 +6,8 @@
 #define CEF_LIBCEF_BROWSER_VIEWS_BROWSER_VIEW_IMPL_H_
 #pragma once
 
+#include <optional>
+
 #include "base/functional/callback_forward.h"
 #include "base/memory/raw_ptr.h"
 #include "base/memory/weak_ptr.h"
@@ -33,6 +35,8 @@ class CefBrowserViewImpl
   CefBrowserViewImpl(const CefBrowserViewImpl&) = delete;
   CefBrowserViewImpl& operator=(const CefBrowserViewImpl&) = delete;
 
+  ~CefBrowserViewImpl() override;
+
   // Create a new CefBrowserView instance. |delegate| may be nullptr.
   // |window_info| will only be used when creating a Chrome child window.
   static CefRefPtr<CefBrowserViewImpl> Create(
@@ -49,7 +53,8 @@ class CefBrowserViewImpl
   static CefRefPtr<CefBrowserViewImpl> CreateForPopup(
       const CefBrowserSettings& settings,
       CefRefPtr<CefBrowserViewDelegate> delegate,
-      bool is_devtools);
+      bool is_devtools,
+      cef_runtime_style_t opener_runtime_style);
 
   // Called from CefBrowserPlatformDelegate[Chrome]Views.
   void WebContentsCreated(content::WebContents* web_contents);
@@ -96,12 +101,17 @@ class CefBrowserViewImpl
   bool IsAlloyStyle() const { return is_alloy_style_; }
   bool IsChromeStyle() const { return !is_alloy_style_; }
 
+  base::WeakPtr<CefBrowserViewImpl> GetWeakPtr() {
+    return weak_ptr_factory_.GetWeakPtr();
+  }
+
  private:
   // Create a new implementation object.
   // Always call Initialize() after creation.
   // |delegate| may be nullptr.
   CefBrowserViewImpl(CefRefPtr<CefBrowserViewDelegate> delegate,
-                     bool is_devtools_popup);
+                     bool is_devtools_popup,
+                     std::optional<cef_runtime_style_t> opener_runtime_style);
 
   void SetPendingBrowserCreateParams(
       const CefWindowInfo& window_info,

libcef/browser/views/native_widget_mac.h

@@ -52,6 +52,7 @@ class CefNativeWidgetMac : public views::NativeWidgetMac {
   bool IsCefWindowInitialized() const;
 
   raw_ptr<BrowserView, AcrossTasksDanglingUntriaged> browser_view_ = nullptr;
+  bool initialized_ = false;
 };
 
 #endif  // CEF_LIBCEF_BROWSER_VIEWS_NATIVE_WIDGET_MAC_H_

libcef/browser/views/native_widget_mac.mm

@@ -138,7 +138,12 @@ void CefNativeWidgetMac::OnWindowFullscreenTransitionComplete() {
 }
 
 void CefNativeWidgetMac::OnWindowInitialized() {
-  if (!browser_view_) {
+  // This connects the native widget with the command dispatcher so accelerators
+  // work even if a browser_view_ is not created later.
+  // The initialized_ check is necessary because the method can be called twice:
+  // 1. From NativeWidgetMac::InitNativeWidget
+  // 2. From ChromeBrowserFrame::Init
+  if (initialized_) {
     return;
   }
 
@@ -146,10 +151,12 @@ void CefNativeWidgetMac::OnWindowInitialized() {
   if (auto* bridge = GetInProcessNSWindowBridge()) {
     bridge->SetCommandDispatcher([[ChromeCommandDispatcherDelegate alloc] init],
                                  [[BrowserWindowCommandHandler alloc] init]);
-  } else {
+    initialized_ = true;
+  } else if (browser_view_) {
     if (auto* host = GetHostForBrowser(browser_view_->browser())) {
       host->GetAppShim()->CreateCommandDispatcherForWidget(
           GetNSWindowHost()->bridged_native_widget_id());
+      initialized_ = true;
     }
   }
 }

libcef/browser/views/overlay_view_host.cc

@@ -280,18 +280,17 @@ void CefOverlayViewHost::SetOverlayBounds(const gfx::Rect& bounds) {
     return;
   }
 
-  gfx::Rect new_bounds = bounds;
-
-  // Keep the result inside the widget.
-  new_bounds.Intersect(window_view_->bounds());
-
-  if (new_bounds == bounds_) {
+  // Empty bounds are not allowed.
+  if (bounds.IsEmpty()) {
     return;
   }
 
   bounds_changing_ = true;
+  bounds_ = bounds;
+
+  // Keep the result inside the widget.
+  bounds_.Intersect(window_view_->bounds());
 
-  bounds_ = new_bounds;
   if (view_->size() != bounds_.size()) {
     view_->SetSize(bounds_.size());
   }
@@ -313,6 +312,11 @@ void CefOverlayViewHost::OnViewBoundsChanged(views::View* observed_view) {
   MoveIfNecessary();
 }
 
+void CefOverlayViewHost::OnViewIsDeleting(views::View* observed_view) {
+  view_ = nullptr;
+  Cleanup();
+}
+
 gfx::Rect CefOverlayViewHost::ComputeBounds() const {
   // This method is only used with corner docking.
   DCHECK_NE(docking_mode_, CEF_DOCKING_MODE_CUSTOM);

libcef/browser/views/overlay_view_host.h

@@ -44,6 +44,7 @@ class CefOverlayViewHost : public views::WidgetDelegate,
 
   // views::ViewObserver methods:
   void OnViewBoundsChanged(views::View* observed_view) override;
+  void OnViewIsDeleting(views::View* observed_view) override;
 
   cef_docking_mode_t docking_mode() const { return docking_mode_; }
   CefRefPtr<CefOverlayController> controller() const { return cef_controller_; }

libcef_dll/cpptoc/browser_host_cpptoc.cc

@@ -9,7 +9,7 @@
 // implementations. See the translator.README.txt file in the tools directory
 // for more information.
 //
-// $hash=434a753c90262b051077f7a79f3106ac52ffbf75$
+// $hash=8a2a8a4853c3869876ffad3e6c175945ac1c5021$
 //
 
 #include "libcef_dll/cpptoc/browser_host_cpptoc.h"
@@ -191,6 +191,24 @@ browser_host_try_close_browser(struct _cef_browser_host_t* self) {
   return _retval;
 }
 
+int CEF_CALLBACK
+browser_host_is_ready_to_be_closed(struct _cef_browser_host_t* self) {
+  shutdown_checker::AssertNotShutdown();
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  DCHECK(self);
+  if (!self) {
+    return 0;
+  }
+
+  // Execute
+  bool _retval = CefBrowserHostCppToC::Get(self)->IsReadyToBeClosed();
+
+  // Return type: bool
+  return _retval;
+}
+
 void CEF_CALLBACK browser_host_set_focus(struct _cef_browser_host_t* self,
                                          int focus) {
   shutdown_checker::AssertNotShutdown();
@@ -1514,6 +1532,7 @@ CefBrowserHostCppToC::CefBrowserHostCppToC() {
   GetStruct()->get_browser = browser_host_get_browser;
   GetStruct()->close_browser = browser_host_close_browser;
   GetStruct()->try_close_browser = browser_host_try_close_browser;
+  GetStruct()->is_ready_to_be_closed = browser_host_is_ready_to_be_closed;
   GetStruct()->set_focus = browser_host_set_focus;
   GetStruct()->get_window_handle = browser_host_get_window_handle;
   GetStruct()->get_opener_window_handle = browser_host_get_opener_window_handle;

libcef_dll/ctocpp/browser_host_ctocpp.cc

@@ -9,7 +9,7 @@
 // implementations. See the translator.README.txt file in the tools directory
 // for more information.
 //
-// $hash=dac19ba091b3acf3e1587b176e28bc9f9c8c8dd0$
+// $hash=2319d794dd3a38c448908114d1b4ea37b34f89dd$
 //
 
 #include "libcef_dll/ctocpp/browser_host_ctocpp.h"
@@ -131,6 +131,23 @@ NO_SANITIZE("cfi-icall") bool CefBrowserHostCToCpp::TryCloseBrowser() {
   return _retval ? true : false;
 }
 
+NO_SANITIZE("cfi-icall") bool CefBrowserHostCToCpp::IsReadyToBeClosed() {
+  shutdown_checker::AssertNotShutdown();
+
+  cef_browser_host_t* _struct = GetStruct();
+  if (CEF_MEMBER_MISSING(_struct, is_ready_to_be_closed)) {
+    return false;
+  }
+
+  // AUTO-GENERATED CONTENT - DELETE THIS COMMENT BEFORE MODIFYING
+
+  // Execute
+  int _retval = _struct->is_ready_to_be_closed(_struct);
+
+  // Return type: bool
+  return _retval ? true : false;
+}
+
 NO_SANITIZE("cfi-icall") void CefBrowserHostCToCpp::SetFocus(bool focus) {
   shutdown_checker::AssertNotShutdown();
 
@@ -1111,8 +1128,8 @@ void CefBrowserHostCToCpp::DragSourceSystemDragEnded() {
 }
 
 NO_SANITIZE("cfi-icall")
-CefRefPtr<
-    CefNavigationEntry> CefBrowserHostCToCpp::GetVisibleNavigationEntry() {
+CefRefPtr<CefNavigationEntry>
+CefBrowserHostCToCpp::GetVisibleNavigationEntry() {
   shutdown_checker::AssertNotShutdown();
 
   cef_browser_host_t* _struct = GetStruct();

libcef_dll/ctocpp/browser_host_ctocpp.h

@@ -9,7 +9,7 @@
 // implementations. See the translator.README.txt file in the tools directory
 // for more information.
 //
-// $hash=9f40e4ce3e46a895b5bf644bebdc2d802c9b598b$
+// $hash=73d8659f17a4ae3319b5bf20807d5c69a1759c04$
 //
 
 #ifndef CEF_LIBCEF_DLL_CTOCPP_BROWSER_HOST_CTOCPP_H_
@@ -41,6 +41,7 @@ class CefBrowserHostCToCpp : public CefCToCppRefCounted<CefBrowserHostCToCpp,
   CefRefPtr<CefBrowser> GetBrowser() override;
   void CloseBrowser(bool force_close) override;
   bool TryCloseBrowser() override;
+  bool IsReadyToBeClosed() override;
   void SetFocus(bool focus) override;
   CefWindowHandle GetWindowHandle() override;
   CefWindowHandle GetOpenerWindowHandle() override;

libcef_dll/wrapper/cef_message_router.cc

@@ -4,6 +4,7 @@
 
 #include "include/wrapper/cef_message_router.h"
 
+#include <algorithm>
 #include <limits>
 #include <map>
 #include <set>

tests/cefclient/browser/default_client_handler.cc

@@ -4,8 +4,16 @@
 
 #include "tests/cefclient/browser/default_client_handler.h"
 
+#include "tests/cefclient/browser/main_context.h"
+#include "tests/cefclient/browser/root_window_manager.h"
+
 namespace client {
 
+DefaultClientHandler::DefaultClientHandler(std::optional<bool> use_alloy_style)
+    : use_alloy_style_(
+          use_alloy_style.value_or(MainContext::Get()->UseAlloyStyleGlobal())) {
+}
+
 // static
 CefRefPtr<DefaultClientHandler> DefaultClientHandler::GetForClient(
     CefRefPtr<CefClient> client) {
@@ -16,4 +24,39 @@ CefRefPtr<DefaultClientHandler> DefaultClientHandler::GetForClient(
   return nullptr;
 }
 
+bool DefaultClientHandler::OnBeforePopup(
+    CefRefPtr<CefBrowser> browser,
+    CefRefPtr<CefFrame> frame,
+    const CefString& target_url,
+    const CefString& target_frame_name,
+    CefLifeSpanHandler::WindowOpenDisposition target_disposition,
+    bool user_gesture,
+    const CefPopupFeatures& popupFeatures,
+    CefWindowInfo& windowInfo,
+    CefRefPtr<CefClient>& client,
+    CefBrowserSettings& settings,
+    CefRefPtr<CefDictionaryValue>& extra_info,
+    bool* no_javascript_access) {
+  CEF_REQUIRE_UI_THREAD();
+
+  if (target_disposition == CEF_WOD_NEW_PICTURE_IN_PICTURE) {
+    // Use default handling for document picture-in-picture popups.
+    client = nullptr;
+    return false;
+  }
+
+  // Used to configure default values.
+  RootWindowConfig config(/*command_line=*/nullptr);
+
+  // Potentially create a new RootWindow for the popup browser that will be
+  // created asynchronously.
+  MainContext::Get()->GetRootWindowManager()->CreateRootWindowAsPopup(
+      config.use_views, use_alloy_style_, config.with_controls,
+      /*is_osr=*/false, /*is_devtools=*/false, popupFeatures, windowInfo,
+      client, settings);
+
+  // Allow popup creation.
+  return false;
+}
+
 }  // namespace client

tests/cefclient/browser/default_client_handler.h

@@ -6,6 +6,8 @@
 #define CEF_TESTS_CEFCLIENT_BROWSER_DEFAULT_CLIENT_HANDLER_H_
 #pragma once
 
+#include <optional>
+
 #include "tests/cefclient/browser/base_client_handler.h"
 
 namespace client {
@@ -14,18 +16,37 @@ namespace client {
 // style only.
 class DefaultClientHandler : public BaseClientHandler {
  public:
-  DefaultClientHandler() = default;
+  // If |use_alloy_style| is nullopt the global default will be used.
+  explicit DefaultClientHandler(
+      std::optional<bool> use_alloy_style = std::nullopt);
 
   // Returns the DefaultClientHandler for |client|, or nullptr if |client| is
   // not a DefaultClientHandler.
   static CefRefPtr<DefaultClientHandler> GetForClient(
       CefRefPtr<CefClient> client);
 
+ protected:
+  bool OnBeforePopup(
+      CefRefPtr<CefBrowser> browser,
+      CefRefPtr<CefFrame> frame,
+      const CefString& target_url,
+      const CefString& target_frame_name,
+      CefLifeSpanHandler::WindowOpenDisposition target_disposition,
+      bool user_gesture,
+      const CefPopupFeatures& popupFeatures,
+      CefWindowInfo& windowInfo,
+      CefRefPtr<CefClient>& client,
+      CefBrowserSettings& settings,
+      CefRefPtr<CefDictionaryValue>& extra_info,
+      bool* no_javascript_access) override;
+
  private:
   // Used to determine the object type.
   virtual const void* GetTypeKey() const override { return &kTypeKey; }
   static constexpr int kTypeKey = 0;
 
+  const bool use_alloy_style_;
+
   IMPLEMENT_REFCOUNTING(DefaultClientHandler);
   DISALLOW_COPY_AND_ASSIGN(DefaultClientHandler);
 };

tests/cefclient/browser/resource.h

@@ -21,6 +21,7 @@
 #define IDC_NAV_STOP 203
 #define ID_QUIT 32500
 #define ID_FIND 32501
+#define ID_POPOUT_OVERLAY 32502
 #define ID_TESTS_FIRST 32700
 #define ID_TESTS_GETSOURCE 32700
 #define ID_TESTS_GETTEXT 32701

tests/cefclient/browser/root_window_manager.cc

@@ -134,8 +134,11 @@ scoped_refptr<RootWindow> RootWindowManager::CreateRootWindowAsPopup(
 
   if (MainContext::Get()->UseDefaultPopup() || (is_devtools && !use_views)) {
     // Use default window creation for the popup. A new |client| instance is
-    // still required by cefclient architecture.
-    client = new DefaultClientHandler();
+    // required by cefclient architecture if the type is not already
+    // DefaultClientHandler.
+    if (!DefaultClientHandler::GetForClient(client)) {
+      client = new DefaultClientHandler(use_alloy_style);
+    }
     return nullptr;
   }
 

tests/cefclient/browser/views_overlay_browser.cc

@@ -0,0 +1,315 @@
+// Copyright (c) 2024 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+
+#include "tests/cefclient/browser/views_overlay_browser.h"
+
+#include "include/views/cef_window.h"
+#include "tests/cefclient/browser/resource.h"
+#include "tests/cefclient/browser/views_window.h"
+
+namespace client {
+
+namespace {
+
+void AddPopOutAccelerator(CefRefPtr<CefWindow> window) {
+  // Add an accelerator to toggle the BrowserView popout. OnAccelerator will be
+  // called when the accelerator is triggered.
+  window->SetAccelerator(ID_POPOUT_OVERLAY, 'O', /*shift_pressed=*/false,
+                         /*ctrl_pressed=*/false, /*alt_pressed=*/true,
+                         /*high_priority=*/true);
+}
+
+// Popout window delegate implementation.
+class PopoutWindowDelegate : public CefWindowDelegate {
+ public:
+  PopoutWindowDelegate(base::WeakPtr<ViewsOverlayBrowser> overlay,
+                       CefRefPtr<CefBrowserView> browser_view)
+      : overlay_(overlay), browser_view_(browser_view) {}
+
+  PopoutWindowDelegate(const PopoutWindowDelegate&) = delete;
+  PopoutWindowDelegate& operator=(const PopoutWindowDelegate&) = delete;
+
+  static PopoutWindowDelegate* GetForWindow(CefRefPtr<CefWindow> window) {
+    return static_cast<PopoutWindowDelegate*>(window->GetDelegate().get());
+  }
+
+  void OnWindowCreated(CefRefPtr<CefWindow> window) override {
+    window->AddChildView(browser_view_);
+    window->Show();
+
+    // Add the popout accelerator to the popout Window.
+    AddPopOutAccelerator(window);
+
+    browser_view_->RequestFocus();
+  }
+
+  bool CanClose(CefRefPtr<CefWindow> window) override {
+    CefRefPtr<CefBrowser> browser =
+        browser_view_ ? browser_view_->GetBrowser() : nullptr;
+
+    if (overlay_ && browser && !browser->GetHost()->IsReadyToBeClosed()) {
+      // Proceed with the window close, but don't close the browser. The browser
+      // will be returned to the overlay in OnWindowClosing().
+      return_to_overlay_ = true;
+      return true;
+    }
+
+    if (browser) {
+      // We must close the browser, either because the popout Window is the
+      // final owner of the BrowserView, or because the browser is ready to be
+      // closed internally (e.g. `window.close()` was called).
+      return browser->GetHost()->TryCloseBrowser();
+    }
+
+    return true;
+  }
+
+  void OnWindowClosing(CefRefPtr<CefWindow> window) override {
+    if (overlay_ && return_to_overlay_) {
+      // Give the browser back to the overlay.
+      overlay_->ToggleBrowserView();
+    }
+  }
+
+  void OnWindowDestroyed(CefRefPtr<CefWindow> window) override {
+    if (overlay_) {
+      overlay_->PopOutWindowDestroyed();
+      overlay_ = nullptr;
+    }
+    browser_view_ = nullptr;
+  }
+
+  cef_runtime_style_t GetWindowRuntimeStyle() override {
+    return browser_view_->GetRuntimeStyle();
+  }
+
+  bool OnAccelerator(CefRefPtr<CefWindow> window, int command_id) override {
+    if (overlay_) {
+      return overlay_->OnAccelerator(window, command_id);
+    }
+    return false;
+  }
+
+  [[nodiscard]] CefRefPtr<CefBrowserView> DetachBrowserView() {
+    overlay_ = nullptr;
+    auto browser_view = browser_view_;
+    browser_view_ = nullptr;
+    return browser_view;
+  }
+
+  void OverlayDestroyed() { overlay_ = nullptr; }
+
+ private:
+  base::WeakPtr<ViewsOverlayBrowser> overlay_;
+  CefRefPtr<CefBrowserView> browser_view_;
+  bool return_to_overlay_ = false;
+
+  IMPLEMENT_REFCOUNTING(PopoutWindowDelegate);
+};
+
+}  // namespace
+
+ViewsOverlayBrowser::ViewsOverlayBrowser(ViewsWindow* owner_window)
+    : owner_window_(owner_window) {}
+
+void ViewsOverlayBrowser::Initialize(
+    CefRefPtr<CefWindow> window,
+    CefRefPtr<CefClient> client,
+    const std::string& url,
+    const CefBrowserSettings& settings,
+    CefRefPtr<CefRequestContext> request_context) {
+  CHECK(!window_);
+  window_ = window;
+  CHECK(window_);
+
+  // Add the accelerator to the main window.
+  AddPopOutAccelerator(window_);
+
+  browser_view_ = CefBrowserView::CreateBrowserView(
+      client, url, settings, nullptr, request_context, this);
+  CHECK(browser_view_);
+
+  // Add the BrowserView to an overlay in the main window.
+  controller_ = window_->AddOverlayView(browser_view_, CEF_DOCKING_MODE_CUSTOM,
+                                        /*can_activate=*/true);
+  CHECK(controller_);
+}
+
+void ViewsOverlayBrowser::Destroy() {
+  window_ = nullptr;
+
+  if (popout_window_) {
+    // The BrowserView is popped out, and the main Window is closed first.
+    // Let the popout Window handle BrowserView destruction.
+    PopoutWindowDelegate::GetForWindow(popout_window_)->OverlayDestroyed();
+    popout_window_->Close();
+    popout_window_ = nullptr;
+  }
+
+  if (controller_) {
+    if (controller_->IsValid()) {
+      controller_->Destroy();
+    }
+    controller_ = nullptr;
+    owner_window_->UpdateDraggableRegions();
+  }
+
+  if (browser_view_) {
+    // We hold the last reference to the BrowserView, and releasing it will
+    // trigger overlay Browser destruction. OnBeforeClose for that Browser may
+    // be called synchronously or asynchronously depending on whether
+    // beforeunload needs to be dispatched.
+    DCHECK(browser_view_->HasOneRef());
+    browser_view_ = nullptr;
+  }
+}
+
+bool ViewsOverlayBrowser::IsValid() const {
+  // Intentionally not checking |popout_window_->IsValid()| here because the
+  // pop-in behavior will be triggered by |popout_window_| closing.
+  return (controller_ && controller_->IsValid()) || popout_window_;
+}
+
+void ViewsOverlayBrowser::ToggleBrowserView() {
+  if (browser_view_) {
+    PopOutBrowserView();
+  } else {
+    PopInBrowserView();
+  }
+
+  owner_window_->UpdateDraggableRegions();
+}
+
+void ViewsOverlayBrowser::PopOutBrowserView() {
+  CHECK(browser_view_);
+
+  DCHECK(controller_ && controller_->IsValid());
+  controller_->Destroy();
+  controller_ = nullptr;
+
+  // We hold the only reference to the BrowserView.
+  DCHECK(browser_view_->HasOneRef());
+
+  // Create a new popout Window and pass ownership of the BrowserView.
+  CHECK(!popout_window_);
+  popout_window_ = CefWindow::CreateTopLevelWindow(
+      new PopoutWindowDelegate(weak_ptr_factory_.GetWeakPtr(), browser_view_));
+  browser_view_ = nullptr;
+}
+
+void ViewsOverlayBrowser::PopInBrowserView() {
+  CHECK(!browser_view_);
+
+  // Resume ownership of the BrowserView and close the popout Window.
+  CHECK(popout_window_);
+  browser_view_ =
+      PopoutWindowDelegate::GetForWindow(popout_window_)->DetachBrowserView();
+  popout_window_->RemoveChildView(browser_view_);
+  popout_window_->Close();
+  popout_window_ = nullptr;
+
+  // We hold the only reference to the BrowserView.
+  DCHECK(browser_view_->HasOneRef());
+
+  // Add the BrowserView to an overlay in the main window.
+  controller_ = window_->AddOverlayView(browser_view_, CEF_DOCKING_MODE_CUSTOM,
+                                        /*can_activate=*/true);
+  CHECK(controller_);
+
+  // Make sure the overlay is positioned correctly.
+  UpdateBounds(last_insets_);
+}
+
+void ViewsOverlayBrowser::UpdateBounds(CefInsets insets) {
+  last_insets_ = insets;
+
+  if (!controller_) {
+    return;
+  }
+
+  // Update location bar size, position and visibility.
+  const auto window_bounds = window_->GetBounds();
+
+  // Client coordinates with insets.
+  CefRect bounds;
+  bounds.x = insets.left;
+  bounds.width = window_bounds.width - insets.left - insets.right;
+  bounds.y = insets.top;
+  bounds.height = window_bounds.height - insets.top - insets.bottom;
+
+  const auto min_size = browser_view_->GetMinimumSize();
+  if (bounds.width < min_size.width || bounds.height < min_size.height) {
+    // Not enough space.
+    controller_->SetVisible(false);
+  } else {
+    controller_->SetSize(CefSize(bounds.width, bounds.height));
+    controller_->SetBounds(bounds);
+    controller_->SetVisible(true);
+  }
+}
+
+void ViewsOverlayBrowser::UpdateDraggableRegions(
+    std::vector<CefDraggableRegion>& window_regions) {
+  if (controller_ && controller_->IsVisible()) {
+    window_regions.emplace_back(controller_->GetBounds(),
+                                /*draggable=*/false);
+  }
+}
+
+bool ViewsOverlayBrowser::OnAccelerator(CefRefPtr<CefWindow> window,
+                                        int command_id) {
+  if (IsValid() && command_id == ID_POPOUT_OVERLAY) {
+    ToggleBrowserView();
+    return true;
+  }
+  return false;
+}
+
+void ViewsOverlayBrowser::PopOutWindowDestroyed() {
+  popout_window_ = nullptr;
+}
+
+CefSize ViewsOverlayBrowser::GetMinimumSize(CefRefPtr<CefView> view) {
+  return CefSize(200, 200);
+}
+
+void ViewsOverlayBrowser::OnBrowserDestroyed(
+    CefRefPtr<CefBrowserView> browser_view,
+    CefRefPtr<CefBrowser> browser) {
+  // Might be popped out currently.
+  if (!controller_) {
+    return;
+  }
+
+  // Destroy the overlay controller if the browser is destroyed first (e.g. via
+  // `window.close()`).
+  controller_->Destroy();
+  controller_ = nullptr;
+  owner_window_->UpdateDraggableRegions();
+}
+
+CefRefPtr<CefBrowserViewDelegate>
+ViewsOverlayBrowser::GetDelegateForPopupBrowserView(
+    CefRefPtr<CefBrowserView> browser_view,
+    const CefBrowserSettings& settings,
+    CefRefPtr<CefClient> client,
+    bool is_devtools) {
+  return owner_window_->GetDelegateForPopupBrowserView(browser_view, settings,
+                                                       client, is_devtools);
+}
+
+bool ViewsOverlayBrowser::OnPopupBrowserViewCreated(
+    CefRefPtr<CefBrowserView> browser_view,
+    CefRefPtr<CefBrowserView> popup_browser_view,
+    bool is_devtools) {
+  return owner_window_->OnPopupBrowserViewCreated(
+      browser_view, popup_browser_view, is_devtools);
+}
+
+cef_runtime_style_t ViewsOverlayBrowser::GetBrowserRuntimeStyle() {
+  // Overlay browser view must always be Alloy style.
+  return CEF_RUNTIME_STYLE_ALLOY;
+}
+
+}  // namespace client

tests/cefclient/browser/views_overlay_browser.h

@@ -0,0 +1,86 @@
+// Copyright (c) 2024 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+
+#ifndef CEF_TESTS_CEFCLIENT_BROWSER_VIEWS_OVERLAY_BROWSER_H_
+#define CEF_TESTS_CEFCLIENT_BROWSER_VIEWS_OVERLAY_BROWSER_H_
+#pragma once
+
+#include "include/base/cef_weak_ptr.h"
+#include "include/views/cef_browser_view.h"
+#include "include/views/cef_browser_view_delegate.h"
+#include "include/views/cef_overlay_controller.h"
+
+namespace client {
+
+class ViewsWindow;
+
+// Implements a browser view that receives absolute positioning on top of the
+// main browser view. All methods must be called on the browser process UI
+// thread.
+class ViewsOverlayBrowser : public CefBrowserViewDelegate {
+ public:
+  explicit ViewsOverlayBrowser(ViewsWindow* owner_window);
+
+  void Initialize(CefRefPtr<CefWindow> window,
+                  CefRefPtr<CefClient> client,
+                  const std::string& url,
+                  const CefBrowserSettings& settings,
+                  CefRefPtr<CefRequestContext> request_context);
+  void Destroy();
+
+  bool IsValid() const;
+
+  // Move the overlay BrowserView to/from a popout Window.
+  void ToggleBrowserView();
+
+  // Update browser bounds.
+  void UpdateBounds(CefInsets insets);
+
+  // Exclude all regions obscured by overlays.
+  void UpdateDraggableRegions(std::vector<CefDraggableRegion>& window_regions);
+
+  bool OnAccelerator(CefRefPtr<CefWindow> window, int command_id);
+
+  void PopOutWindowDestroyed();
+
+ private:
+  // CefViewDelegate methods:
+  CefSize GetMinimumSize(CefRefPtr<CefView> view) override;
+
+  // CefBrowserViewDelegate methods:
+  void OnBrowserDestroyed(CefRefPtr<CefBrowserView> browser_view,
+                          CefRefPtr<CefBrowser> browser) override;
+  CefRefPtr<CefBrowserViewDelegate> GetDelegateForPopupBrowserView(
+      CefRefPtr<CefBrowserView> browser_view,
+      const CefBrowserSettings& settings,
+      CefRefPtr<CefClient> client,
+      bool is_devtools) override;
+  bool OnPopupBrowserViewCreated(CefRefPtr<CefBrowserView> browser_view,
+                                 CefRefPtr<CefBrowserView> popup_browser_view,
+                                 bool is_devtools) override;
+  cef_runtime_style_t GetBrowserRuntimeStyle() override;
+
+  // Move the BrowserView to a new top-level Window.
+  void PopOutBrowserView();
+
+  // Return the BrowserView to the overlay.
+  void PopInBrowserView();
+
+  ViewsWindow* const owner_window_;
+  CefRefPtr<CefWindow> window_;
+  CefRefPtr<CefBrowserView> browser_view_;
+  CefRefPtr<CefOverlayController> controller_;
+  CefInsets last_insets_;
+
+  CefRefPtr<CefWindow> popout_window_;
+
+  base::WeakPtrFactory<ViewsOverlayBrowser> weak_ptr_factory_{this};
+
+  IMPLEMENT_REFCOUNTING(ViewsOverlayBrowser);
+  DISALLOW_COPY_AND_ASSIGN(ViewsOverlayBrowser);
+};
+
+}  // namespace client
+
+#endif  // CEF_TESTS_CEFCLIENT_BROWSER_VIEWS_OVERLAY_BROWSER_H_

tests/cefclient/browser/views_window.cc

@@ -12,6 +12,7 @@
 #include "include/cef_i18n_util.h"
 #include "include/views/cef_box_layout.h"
 #include "include/wrapper/cef_helpers.h"
+#include "tests/cefclient/browser/default_client_handler.h"
 #include "tests/cefclient/browser/main_context.h"
 #include "tests/cefclient/browser/resource.h"
 #include "tests/cefclient/browser/views_style.h"
@@ -146,6 +147,14 @@ CefRefPtr<ViewsWindow> ViewsWindow::Create(
   CefRefPtr<ViewsWindow> views_window =
       new ViewsWindow(type, delegate, nullptr, command_line);
 
+  // Only create an overlay browser for a primary window.
+  if (command_line->HasSwitch(switches::kShowOverlayBrowser)) {
+    views_window->with_overlay_browser_ = true;
+    views_window->initial_url_ = url;
+    views_window->settings_ = settings;
+    views_window->request_context_ = request_context;
+  }
+
   const auto expected_browser_runtime_style = views_window->use_alloy_style_
                                                   ? CEF_RUNTIME_STYLE_ALLOY
                                                   : CEF_RUNTIME_STYLE_CHROME;
@@ -345,6 +354,8 @@ void ViewsWindow::SetDraggableRegions(
     return;
   }
 
+  last_regions_ = regions;
+
   // Convert the regions from BrowserView to Window coordinates.
   std::vector<CefDraggableRegion> window_regions = regions;
   for (auto& region : window_regions) {
@@ -359,6 +370,11 @@ void ViewsWindow::SetDraggableRegions(
     overlay_controls_->UpdateDraggableRegions(window_regions);
   }
 
+  if (overlay_browser_) {
+    // Exclude all regions obscured by overlays.
+    overlay_browser_->UpdateDraggableRegions(window_regions);
+  }
+
   window_->SetDraggableRegions(window_regions);
 }
 
@@ -434,6 +450,10 @@ void ViewsWindow::SetTitlebarHeight(const std::optional<float>& height) {
   NudgeWindow();
 }
 
+void ViewsWindow::UpdateDraggableRegions() {
+  SetDraggableRegions(last_regions_);
+}
+
 CefRefPtr<CefBrowserViewDelegate> ViewsWindow::GetDelegateForPopupBrowserView(
     CefRefPtr<CefBrowserView> browser_view,
     const CefBrowserSettings& settings,
@@ -900,6 +920,8 @@ bool ViewsWindow::OnAccelerator(CefRefPtr<CefWindow> window, int command_id) {
   if (command_id == ID_QUIT) {
     delegate_->OnExit();
     return true;
+  } else if (overlay_browser_) {
+    return overlay_browser_->OnAccelerator(window, command_id);
   }
 
   return false;
@@ -1001,6 +1023,19 @@ void ViewsWindow::OnWindowChanged(CefRefPtr<CefView> view, bool added) {
                                     CreateLocationBar(),
                                     chrome_toolbar_type_ != CEF_CTT_NONE);
     }
+
+    if (with_overlay_browser_) {
+      overlay_browser_ = new ViewsOverlayBrowser(this);
+
+      // Use default behavior for the overlay browser. A new |client| instance
+      // is still required by cefclient architecture.
+      CefRefPtr<CefClient> client =
+          new DefaultClientHandler(/*use_alloy_style=*/true);
+
+      overlay_browser_->Initialize(window_, client, initial_url_, settings_,
+                                   request_context_);
+      request_context_ = nullptr;
+    }
   } else {
     // Remove any controls that may include the Chrome toolbar before removing
     // the BrowserView.
@@ -1015,6 +1050,10 @@ void ViewsWindow::OnWindowChanged(CefRefPtr<CefView> view, bool added) {
         location_bar_ = nullptr;
       }
     }
+    if (overlay_browser_) {
+      overlay_browser_->Destroy();
+      overlay_browser_ = nullptr;
+    }
   }
 }
 
@@ -1028,6 +1067,12 @@ void ViewsWindow::OnLayoutChanged(CefRefPtr<CefView> view,
   if (overlay_controls_) {
     overlay_controls_->UpdateControls();
   }
+
+  if (overlay_browser_) {
+    // TODO: Consider modifying insets based on toolbar visibility.
+    CefInsets window_insets(200, 200, 200, 200);
+    overlay_browser_->UpdateBounds(window_insets);
+  }
 }
 
 void ViewsWindow::OnThemeChanged(CefRefPtr<CefView> view) {
@@ -1064,9 +1109,9 @@ ViewsWindow::ViewsWindow(WindowType type,
   with_controls_ = is_normal_type && delegate_->WithControls();
 
   const bool hide_frame = command_line->HasSwitch(switches::kHideFrame);
-  const bool hide_overlays =
-      !is_normal_type || command_line->HasSwitch(switches::kHideOverlays);
-  const bool hide_toolbar = hide_overlays && !with_controls_;
+  const bool show_overlays = is_normal_type && hide_frame && !with_controls_ &&
+                             !command_line->HasSwitch(switches::kHideOverlays);
+  const bool hide_toolbar = !show_overlays && !with_controls_;
   const bool show_window_buttons =
       command_line->HasSwitch(switches::kShowWindowButtons);
   accepts_first_mouse_ = command_line->HasSwitch(switches::kAcceptsFirstMouse);
@@ -1075,7 +1120,7 @@ ViewsWindow::ViewsWindow(WindowType type,
   frameless_ = hide_frame;
 
   // With an overlay that mimics window controls.
-  with_overlay_controls_ = hide_frame && !hide_overlays && !with_controls_;
+  with_overlay_controls_ = show_overlays;
 
   // If window has frame or flag passed explicitly
   with_standard_buttons_ = !frameless_ || show_window_buttons;
@@ -1313,12 +1358,12 @@ void ViewsWindow::SetMenuFocusable(bool focusable) {
 
   if (menu_bar_) {
     menu_bar_->SetMenuFocusable(focusable);
-  } else {
-    window_->GetViewForID(ID_MENU_BUTTON)->SetFocusable(focusable);
+  } else if (menu_button_) {
+    menu_button_->SetFocusable(focusable);
 
     if (focusable) {
       // Give focus to menu button.
-      window_->GetViewForID(ID_MENU_BUTTON)->RequestFocus();
+      menu_button_->RequestFocus();
     }
   }
 

tests/cefclient/browser/views_window.h

@@ -27,6 +27,7 @@
 #include "tests/cefclient/browser/image_cache.h"
 #include "tests/cefclient/browser/root_window.h"
 #include "tests/cefclient/browser/views_menu_bar.h"
+#include "tests/cefclient/browser/views_overlay_browser.h"
 #include "tests/cefclient/browser/views_overlay_controls.h"
 
 namespace client {
@@ -128,6 +129,8 @@ class ViewsWindow : public CefBrowserViewDelegate,
                                    std::optional<CefRect>& dip_bounds);
   void SetTitlebarHeight(const std::optional<float>& height);
 
+  void UpdateDraggableRegions();
+
   // CefBrowserViewDelegate methods:
   CefRefPtr<CefBrowserViewDelegate> GetDelegateForPopupBrowserView(
       CefRefPtr<CefBrowserView> browser_view,
@@ -251,7 +254,7 @@ class ViewsWindow : public CefBrowserViewDelegate,
   void NudgeWindow();
 
   const WindowType type_;
-  Delegate* delegate_;  // Not owned by this object.
+  Delegate* const delegate_;  // Not owned by this object.
   const bool use_alloy_style_;
   bool use_alloy_style_window_;
   CefRefPtr<CefBrowserView> browser_view_;
@@ -280,6 +283,13 @@ class ViewsWindow : public CefBrowserViewDelegate,
 
   CefRefPtr<ViewsOverlayControls> overlay_controls_;
 
+  // Overlay browser view state.
+  bool with_overlay_browser_ = false;
+  std::string initial_url_;
+  CefBrowserSettings settings_;
+  CefRefPtr<CefRequestContext> request_context_;
+  CefRefPtr<ViewsOverlayBrowser> overlay_browser_;
+
   std::optional<float> default_titlebar_height_;
   std::optional<float> override_titlebar_height_;
 
@@ -293,6 +303,8 @@ class ViewsWindow : public CefBrowserViewDelegate,
   bool can_go_back_ = false;
   bool can_go_forward_ = false;
 
+  std::vector<CefDraggableRegion> last_regions_;
+
   IMPLEMENT_REFCOUNTING(ViewsWindow);
   DISALLOW_COPY_AND_ASSIGN(ViewsWindow);
 };

tests/ceftests/life_span_unittest.cc

@@ -6,6 +6,7 @@
 #include "include/test/cef_test_helpers.h"
 #include "include/wrapper/cef_closure_task.h"
 #include "tests/ceftests/routing_test_handler.h"
+#include "tests/ceftests/test_util.h"
 #include "tests/gtest/include/gtest/gtest.h"
 
 namespace {
@@ -58,6 +59,8 @@ class LifeSpanTestHandler : public RoutingTestHandler {
   }
 
   bool DoClose(CefRefPtr<CefBrowser> browser) override {
+    EXPECT_TRUE(browser->GetHost()->IsReadyToBeClosed());
+
     if (executing_delay_close_) {
       return false;
     }
@@ -75,6 +78,8 @@ class LifeSpanTestHandler : public RoutingTestHandler {
   }
 
   void OnBeforeClose(CefRefPtr<CefBrowser> browser) override {
+    EXPECT_TRUE(browser->GetHost()->IsReadyToBeClosed());
+
     if (!executing_delay_close_) {
       got_before_close_.yes();
       EXPECT_TRUE(browser->IsSame(GetBrowser()));
@@ -87,6 +92,8 @@ class LifeSpanTestHandler : public RoutingTestHandler {
                             const CefString& message_text,
                             bool is_reload,
                             CefRefPtr<CefJSDialogCallback> callback) override {
+    EXPECT_FALSE(browser->GetHost()->IsReadyToBeClosed());
+
     if (executing_delay_close_) {
       callback->Continue(true, CefString());
       return true;
@@ -124,6 +131,8 @@ class LifeSpanTestHandler : public RoutingTestHandler {
       CefExecuteJavaScriptWithUserGestureForTests(frame, CefString());
     }
 
+    EXPECT_FALSE(browser->GetHost()->IsReadyToBeClosed());
+
     // Attempt to close the browser.
     CloseBrowser(browser, settings_.force_close);
   }
@@ -180,12 +189,15 @@ class LifeSpanTestHandler : public RoutingTestHandler {
 
 TEST(LifeSpanTest, DoCloseAllow) {
   LifeSpanTestHandler::Settings settings;
-  settings.allow_do_close = true;
   CefRefPtr<LifeSpanTestHandler> handler = new LifeSpanTestHandler(settings);
   handler->ExecuteTest();
 
   EXPECT_TRUE(handler->got_after_created_);
-  EXPECT_TRUE(handler->got_do_close_);
+  if (handler->use_alloy_style_browser()) {
+    EXPECT_TRUE(handler->got_do_close_);
+  } else {
+    EXPECT_FALSE(handler->got_do_close_);
+  }
   EXPECT_TRUE(handler->got_before_close_);
   EXPECT_FALSE(handler->got_before_unload_dialog_);
   EXPECT_TRUE(handler->got_unload_message_);
@@ -197,13 +209,16 @@ TEST(LifeSpanTest, DoCloseAllow) {
 
 TEST(LifeSpanTest, DoCloseAllowForce) {
   LifeSpanTestHandler::Settings settings;
-  settings.allow_do_close = true;
   settings.force_close = true;
   CefRefPtr<LifeSpanTestHandler> handler = new LifeSpanTestHandler(settings);
   handler->ExecuteTest();
 
   EXPECT_TRUE(handler->got_after_created_);
-  EXPECT_TRUE(handler->got_do_close_);
+  if (handler->use_alloy_style_browser()) {
+    EXPECT_TRUE(handler->got_do_close_);
+  } else {
+    EXPECT_FALSE(handler->got_do_close_);
+  }
   EXPECT_TRUE(handler->got_before_close_);
   EXPECT_FALSE(handler->got_before_unload_dialog_);
   EXPECT_TRUE(handler->got_unload_message_);
@@ -214,6 +229,11 @@ TEST(LifeSpanTest, DoCloseAllowForce) {
 }
 
 TEST(LifeSpanTest, DoCloseDisallow) {
+  // Test not supported with Chrome style browser.
+  if (!UseAlloyStyleBrowserGlobal()) {
+    return;
+  }
+
   LifeSpanTestHandler::Settings settings;
   settings.allow_do_close = false;
   CefRefPtr<LifeSpanTestHandler> handler = new LifeSpanTestHandler(settings);
@@ -231,6 +251,11 @@ TEST(LifeSpanTest, DoCloseDisallow) {
 }
 
 TEST(LifeSpanTest, DoCloseDisallowForce) {
+  // Test not supported with Chrome style browser.
+  if (!UseAlloyStyleBrowserGlobal()) {
+    return;
+  }
+
   LifeSpanTestHandler::Settings settings;
   settings.allow_do_close = false;
   settings.force_close = true;
@@ -249,6 +274,11 @@ TEST(LifeSpanTest, DoCloseDisallowForce) {
 }
 
 TEST(LifeSpanTest, DoCloseDisallowWithOnUnloadAllow) {
+  // Test not supported with Chrome style browser.
+  if (!UseAlloyStyleBrowserGlobal()) {
+    return;
+  }
+
   LifeSpanTestHandler::Settings settings;
   settings.allow_do_close = false;
   settings.add_onunload_handler = true;
@@ -269,14 +299,17 @@ TEST(LifeSpanTest, DoCloseDisallowWithOnUnloadAllow) {
 
 TEST(LifeSpanTest, DoCloseAllowWithOnUnloadForce) {
   LifeSpanTestHandler::Settings settings;
-  settings.allow_do_close = true;
   settings.add_onunload_handler = true;
   settings.force_close = true;
   CefRefPtr<LifeSpanTestHandler> handler = new LifeSpanTestHandler(settings);
   handler->ExecuteTest();
 
   EXPECT_TRUE(handler->got_after_created_);
-  EXPECT_TRUE(handler->got_do_close_);
+  if (handler->use_alloy_style_browser()) {
+    EXPECT_TRUE(handler->got_do_close_);
+  } else {
+    EXPECT_FALSE(handler->got_do_close_);
+  }
   EXPECT_TRUE(handler->got_before_close_);
   EXPECT_TRUE(handler->got_before_unload_dialog_);
   EXPECT_TRUE(handler->got_unload_message_);
@@ -287,6 +320,11 @@ TEST(LifeSpanTest, DoCloseAllowWithOnUnloadForce) {
 }
 
 TEST(LifeSpanTest, DoCloseDisallowWithOnUnloadForce) {
+  // Test not supported with Chrome style browser.
+  if (!UseAlloyStyleBrowserGlobal()) {
+    return;
+  }
+
   LifeSpanTestHandler::Settings settings;
   settings.allow_do_close = false;
   settings.add_onunload_handler = true;
@@ -313,7 +351,11 @@ TEST(LifeSpanTest, OnUnloadAllow) {
   handler->ExecuteTest();
 
   EXPECT_TRUE(handler->got_after_created_);
-  EXPECT_TRUE(handler->got_do_close_);
+  if (handler->use_alloy_style_browser()) {
+    EXPECT_TRUE(handler->got_do_close_);
+  } else {
+    EXPECT_FALSE(handler->got_do_close_);
+  }
   EXPECT_TRUE(handler->got_before_close_);
   EXPECT_TRUE(handler->got_before_unload_dialog_);
   EXPECT_TRUE(handler->got_unload_message_);

tests/ceftests/test_handler.cc

@@ -322,6 +322,8 @@ void TestHandler::OnAfterCreated(CefRefPtr<CefBrowser> browser) {
 void TestHandler::OnBeforeClose(CefRefPtr<CefBrowser> browser) {
   EXPECT_UI_THREAD();
 
+  EXPECT_TRUE(browser->GetHost()->IsReadyToBeClosed());
+
   // Free the browser pointer so that the browser can be destroyed.
   const int browser_id = browser->GetIdentifier();
   BrowserMap::iterator it = browser_map_.find(browser_id);

tests/ceftests/views/window_unittest.cc

@@ -522,68 +522,21 @@ void WindowIconFramelessImpl(CefRefPtr<CefWaitableEvent> event) {
   TestWindowDelegate::RunTest(event, std::move(config));
 }
 
-const int kChar = 'A';
-const int kCloseWindowId = 2;
+constexpr int kChar = 'A';
+constexpr int kCloseWindowId = 2;
 bool got_accelerator;
-int got_key_event_alt_count;
-bool got_key_event_char;
 
 void TriggerAccelerator(CefRefPtr<CefWindow> window) {
   window->SendKeyPress(kChar, EVENTFLAG_ALT_DOWN);
 }
 
-bool OnKeyEvent(CefRefPtr<CefWindow> window, const CefKeyEvent& event) {
-  if (event.type != KEYEVENT_RAWKEYDOWN) {
-    return false;
-  }
-
-  if (event.windows_key_code == VK_MENU) {
-    // First we get the ALT key press in all cases.
-    EXPECT_FALSE(got_key_event_char);
-    if (got_key_event_alt_count == 0) {
-      EXPECT_FALSE(got_accelerator);
-    } else {
-      EXPECT_TRUE(got_accelerator);
-    }
-
-    EXPECT_EQ(EVENTFLAG_ALT_DOWN, static_cast<int>(event.modifiers));
-    got_key_event_alt_count++;
-  } else if (event.windows_key_code == kChar) {
-    // Then we get the char key press with the ALT modifier if the accelerator
-    // isn't registered.
-    EXPECT_TRUE(got_accelerator);
-    EXPECT_EQ(got_key_event_alt_count, 2);
-    EXPECT_FALSE(got_key_event_char);
-
-    EXPECT_EQ(EVENTFLAG_ALT_DOWN, static_cast<int>(event.modifiers));
-    got_key_event_char = true;
-
-    // Call this method just to make sure it doesn't crash.
-    window->RemoveAllAccelerators();
-
-    // End the test by closing the Window.
-    window->Close();
-
-    return true;
-  }
-
-  return false;
-}
-
 bool OnAccelerator(CefRefPtr<CefWindow> window, int command_id) {
   EXPECT_FALSE(got_accelerator);
-  EXPECT_EQ(got_key_event_alt_count, 1);
-  EXPECT_FALSE(got_key_event_char);
 
   EXPECT_EQ(kCloseWindowId, command_id);
   got_accelerator = true;
 
-  // Remove the accelerator.
-  window->RemoveAccelerator(kCloseWindowId);
-
-  // Now send the event without the accelerator registered. Should result in a
-  // call to OnKeyEvent.
-  TriggerAccelerator(window);
+  window->Close();
 
   return true;
 }
@@ -598,25 +551,15 @@ void RunWindowAccelerator(CefRefPtr<CefWindow> window) {
 
 void VerifyWindowAccelerator(CefRefPtr<CefWindow> window) {
   EXPECT_TRUE(got_accelerator);
-  EXPECT_EQ(got_key_event_alt_count, 2);
-  EXPECT_TRUE(got_key_event_char);
 }
 
-// Expected order of events:
-// 1. OnKeyEvent for ALT key press.
-// 2. OnAccelerator for ALT+Char key press (with accelerator registered).
-// 3. OnKeyEvent for ALT key press.
-// 4. OnKeyEvent for ALT+Char key press (without accelerator registered).
 void WindowAcceleratorImpl(CefRefPtr<CefWaitableEvent> event) {
   got_accelerator = false;
-  got_key_event_alt_count = 0;
-  got_key_event_char = false;
 
   auto config = std::make_unique<TestWindowDelegate::Config>();
   config->on_window_created = base::BindOnce(RunWindowAccelerator);
   config->on_window_destroyed = base::BindOnce(VerifyWindowAccelerator);
   config->on_accelerator = base::BindRepeating(OnAccelerator);
-  config->on_key_event = base::BindRepeating(OnKeyEvent);
   config->close_window = false;
   TestWindowDelegate::RunTest(event, std::move(config));
 }

tests/shared/common/client_switches.cc

@@ -58,5 +58,6 @@ const char kHideWindowOnClose[] = "hide-window-on-close";
 const char kAcceptsFirstMouse[] = "accepts-first-mouse";
 const char kUseAlloyStyle[] = "use-alloy-style";
 const char kUseChromeStyleWindow[] = "use-chrome-style-window";
+const char kShowOverlayBrowser[] = "show-overlay-browser";
 
 }  // namespace client::switches

tests/shared/common/client_switches.h

@@ -52,6 +52,7 @@ extern const char kHideWindowOnClose[];
 extern const char kAcceptsFirstMouse[];
 extern const char kUseAlloyStyle[];
 extern const char kUseChromeStyleWindow[];
+extern const char kShowOverlayBrowser[];
 
 }  // namespace client::switches