chrome: Support unload handlers with TryCloseBrowser

TryCloseBrowser should potentially trigger JavaScript unload handlers
and return false. Add CefBrowserHost::IsReadyToBeClosed for detecting
mandatory close state. Enable, for Chrome style browsers, LifeSpanTest
that don't require DoClose(). Update related documentation.

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
+  /// Request that the browser close. Closing a browser is a multi-stage process
-  /// be fired. If |force_close| is false (0) the event handler, if any, will be
+  /// that may complete either synchronously or asynchronously, and involves
-  /// allowed to prompt the user and the user can optionally cancel the close.
+  /// callbacks such as cef_life_span_handler_t::DoClose (Alloy style only),
-  /// If |force_close| is true (1) the prompt will not be displayed and the
+  /// cef_life_span_handler_t::OnBeforeClose, and a top-level window close
-  /// close will proceed. Results in a call to
+  /// handler such as cef_window_delegate_t::CanClose (or platform-specific
-  /// cef_life_span_handler_t::do_close() if the event handler allows the close
+  /// equivalent). In some cases a close request may be delayed or canceled by
-  /// or if |force_close| is true (1). See cef_life_span_handler_t::do_close()
+  /// the user. Using try_close_browser() instead of close_browser() is
-  /// documentation for additional usage information.
+  /// 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
+  /// Helper for closing a browser. This is similar in behavior to
-  /// close handler (if any). Internally this calls CloseBrowser(false (0)) if
+  /// CLoseBrowser(false (0)) but returns a boolean to reflect the immediate
-  /// the close has not yet been initiated. This function returns false (0)
+  /// close status. Call this function from a top-level window close handler
-  /// while the close is pending and true (1) after the close has completed. See
+  /// such as cef_window_delegate_t::CanClose (or platform-specific equivalent)
-  /// close_browser() and cef_life_span_handler_t::do_close() documentation for
+  /// to request that the browser close, and return the result to indicate if
-  /// additional usage information. This function must be called on the browser
+  /// the window close should proceed. Returns false (0) if the close will be
-  /// process UI thread.
+  /// 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
+  /// Called when an Alloy style browser is ready to be closed, meaning that the
-  /// directly from a call to cef_browser_host_t::*close_browser() or indirectly
+  /// close has already been initiated and that JavaScript unload handlers have
-  /// if the browser is parented to a top-level window created by CEF and the
+  /// already executed or should be ignored. This may result directly from a
-  /// user attempts to close that window (by clicking the 'X', for example). The
+  /// call to cef_browser_host_t::[Try]close_browser() or indirectly if the
-  /// do_close() function will be called after the JavaScript 'onunload' event
+  /// browser's top-level parent window was created by CEF and the user attempts
-  /// has been fired.
+  /// 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
+  /// An application should handle top-level parent window close notifications
-  /// calling cef_browser_host_t::try_close_browser() or
+  /// 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
+  /// When windowed rendering is enabled CEF will create an internal child
-  /// view to host the browser. In that case returning false (0) from do_close()
+  /// window/view to host the browser. In that case returning false (0) from
-  /// will send the standard close notification to the browser's top-level owner
+  /// do_close() will send the standard close notification to the browser's top-
-  /// window (e.g. WM_CLOSE on Windows, performClose: on OS X, "delete_event" on
+  /// level parent window (e.g. WM_CLOSE on Windows, performClose: on OS X,
-  /// Linux or cef_window_delegate_t::can_close() callback from Views). If the
+  /// "delete_event" on Linux or cef_window_delegate_t::can_close() callback
-  /// browser's host window/view has already been destroyed (via view hierarchy
+  /// from Views).
-  /// 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 disabled returning false (0) from do_close()
+  /// When windowed rendering is disabled there is no internal window/view and
-  /// will cause the browser object to be destroyed immediately.
+  /// 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
+  /// 6.  Application's do_close() handler is called and returns false (0) by
-  ///     (because DoClose() returned false by default).
+  ///     default.
-  /// 7.  Application's top-level window receives the close notification and
+  /// 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
+  /// 9.  Application's top-level window is destroyed, triggering destruction
-  /// on_before_close() handler is called and the browser object
+  ///     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.
+  ///     allows the window to close based on the flag from #6A.
-  /// 9.  Application's top-level window is destroyed. 10. Application's
+  /// 9.  Application's top-level window is destroyed, triggering destruction
-  /// on_before_close() handler is called and the browser object
+  ///     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
+  /// Request that the browser close. Closing a browser is a multi-stage process
-  /// be fired. If |force_close| is false the event handler, if any, will be
+  /// that may complete either synchronously or asynchronously, and involves
-  /// allowed to prompt the user and the user can optionally cancel the close.
+  /// callbacks such as CefLifeSpanHandler::DoClose (Alloy style only),
-  /// If |force_close| is true the prompt will not be displayed and the close
+  /// CefLifeSpanHandler::OnBeforeClose, and a top-level window close handler
-  /// will proceed. Results in a call to CefLifeSpanHandler::DoClose() if the
+  /// such as CefWindowDelegate::CanClose (or platform-specific equivalent). In
-  /// event handler allows the close or if |force_close| is true. See
+  /// some cases a close request may be delayed or canceled by the user. Using
-  /// CefLifeSpanHandler::DoClose() documentation for additional usage
+  /// TryCloseBrowser() instead of CloseBrowser() is recommended for most use
-  /// information.
+  /// 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
+  /// Helper for closing a browser. This is similar in behavior to
-  /// close handler (if any). Internally this calls CloseBrowser(false) if the
+  /// CLoseBrowser(false) but returns a boolean to reflect the immediate close
-  /// close has not yet been initiated. This method returns false while the
+  /// status. Call this method from a top-level window close handler such as
-  /// close is pending and true after the close has completed. See
+  /// CefWindowDelegate::CanClose (or platform-specific equivalent) to request
-  /// CloseBrowser() and CefLifeSpanHandler::DoClose() documentation for
+  /// that the browser close, and return the result to indicate if the window
-  /// additional usage information. This method must be called on the browser
+  /// close should proceed. Returns false if the close will be delayed
-  /// process UI thread.
+  /// (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
+  /// Called when an Alloy style browser is ready to be closed, meaning that the
-  /// directly from a call to CefBrowserHost::*CloseBrowser() or indirectly if
+  /// close has already been initiated and that JavaScript unload handlers have
-  /// the browser is parented to a top-level window created by CEF and the user
+  /// already executed or should be ignored. This may result directly from a
-  /// attempts to close that window (by clicking the 'X', for example). The
+  /// call to CefBrowserHost::[Try]CloseBrowser() or indirectly if the browser's
-  /// DoClose() method will be called after the JavaScript 'onunload' event has
+  /// top-level parent window was created by CEF and the user attempts to
-  /// been fired.
+  /// 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
+  /// An application should handle top-level parent window close notifications
-  /// calling CefBrowserHost::TryCloseBrowser() or
+  /// 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
+  /// When windowed rendering is enabled CEF will create an internal child
-  /// view to host the browser. In that case returning false from DoClose() will
+  /// window/view to host the browser. In that case returning false from
-  /// send the standard close notification to the browser's top-level owner
+  /// DoClose() will send the standard close notification to the browser's
-  /// window (e.g. WM_CLOSE on Windows, performClose: on OS X, "delete_event" on
+  /// top-level parent window (e.g. WM_CLOSE on Windows, performClose: on OS X,
-  /// Linux or CefWindowDelegate::CanClose() callback from Views). If the
+  /// "delete_event" on Linux or CefWindowDelegate::CanClose() callback from
-  /// browser's host window/view has already been destroyed (via view hierarchy
+  /// Views).
-  /// 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 disabled returning false from DoClose() will
+  /// When windowed rendering is disabled there is no internal window/view
-  /// cause the browser object to be destroyed immediately.
+  /// 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
+  /// 6.  Application's DoClose() handler is called and returns false by
-  ///     (because DoClose() returned false by default).
+  ///     default.
-  /// 7.  Application's top-level window receives the close notification and
+  /// 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 top-level window is destroyed, triggering destruction
-  /// 9.  Application's OnBeforeClose() handler is called and the browser object
+  ///     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.
+  ///     allows the window to close based on the flag from #6A.
-  /// 9.  Application's top-level window is destroyed.
+  /// 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/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,
+  CEF_POST_TASK(CEF_UIT,
-                                        this, force_close));
+                base::BindOnce(&ChromeBrowserHostImpl::DoCloseBrowser, this));
 }
 
 bool ChromeBrowserHostImpl::TryCloseBrowser() {
-  // TODO(chrome): Handle the case where the browser may not close immediately.
+  if (!CEF_CURRENTLY_ON_UIT()) {
-  CloseBrowser(true);
+    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_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<
+CefRefPtr<CefNavigationEntry>
-    CefNavigationEntry> CefBrowserHostCToCpp::GetVisibleNavigationEntry() {
+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;

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);