Fix crash when closing an OSR browser (fixes issue #2919)

Release the Compositor before the WebContents is destroyed to match
the behavior in non-OSR code.

libcef/browser/osr/browser_platform_delegate_osr.cc

@@ -71,6 +71,20 @@ void CefBrowserPlatformDelegateOsr::BrowserCreated(
   }
 }
 
+void CefBrowserPlatformDelegateOsr::NotifyBrowserDestroyed() {
+  content::WebContents* web_contents = browser_->web_contents();
+  content::RenderViewHost* host = web_contents->GetRenderViewHost();
+  if (host) {
+    CefRenderWidgetHostViewOSR* view =
+        static_cast<CefRenderWidgetHostViewOSR*>(host->GetWidget()->GetView());
+    if (view) {
+      view->ReleaseCompositor();
+    }
+  }
+
+  CefBrowserPlatformDelegateAlloy::NotifyBrowserDestroyed();
+}
+
 void CefBrowserPlatformDelegateOsr::BrowserDestroyed(
     CefBrowserHostImpl* browser) {
   CefBrowserPlatformDelegateAlloy::BrowserDestroyed(browser);

libcef/browser/osr/browser_platform_delegate_osr.h

@@ -27,6 +27,7 @@ class CefBrowserPlatformDelegateOsr
   void WebContentsCreated(content::WebContents* web_contents,
                           bool owned) override;
   void BrowserCreated(CefBrowserHostImpl* browser) override;
+  void NotifyBrowserDestroyed() override;
   void BrowserDestroyed(CefBrowserHostImpl* browser) override;
   SkColor GetBackgroundColor() const override;
   void WasResized() override;

libcef/browser/osr/render_widget_host_view_osr.cc

@@ -25,6 +25,7 @@
 #include "components/viz/common/frame_sinks/begin_frame_args.h"
 #include "components/viz/common/frame_sinks/copy_output_request.h"
 #include "components/viz/common/frame_sinks/delay_based_time_source.h"
+#include "components/viz/common/surfaces/frame_sink_id_allocator.h"
 #include "components/viz/common/switches.h"
 #include "content/browser/bad_message.h"
 #include "content/browser/gpu/gpu_data_manager_impl.h"
@@ -291,6 +292,23 @@ CefRenderWidgetHostViewOSR::CefRenderWidgetHostViewOSR(
 }
 
 CefRenderWidgetHostViewOSR::~CefRenderWidgetHostViewOSR() {
+  ReleaseCompositor();
+  root_layer_.reset(nullptr);
+
+  DCHECK(!parent_host_view_);
+  DCHECK(!popup_host_view_);
+  DCHECK(!child_host_view_);
+  DCHECK(guest_host_views_.empty());
+
+  if (text_input_manager_)
+    text_input_manager_->RemoveObserver(this);
+}
+
+void CefRenderWidgetHostViewOSR::ReleaseCompositor() {
+  if (!compositor_) {
+    return;  // already released
+  }
+
   // Marking the DelegatedFrameHost as removed from the window hierarchy is
   // necessary to remove all connections to its old ui::Compositor.
   if (is_showing_) {
@@ -301,15 +319,6 @@ CefRenderWidgetHostViewOSR::~CefRenderWidgetHostViewOSR() {
 
   delegated_frame_host_.reset(nullptr);
   compositor_.reset(nullptr);
-  root_layer_.reset(nullptr);
-
-  DCHECK(!parent_host_view_);
-  DCHECK(!popup_host_view_);
-  DCHECK(!child_host_view_);
-  DCHECK(guest_host_views_.empty());
-
-  if (text_input_manager_)
-    text_input_manager_->RemoveObserver(this);
 }
 
 // Called for full-screen widgets.
@@ -351,7 +360,9 @@ bool CefRenderWidgetHostViewOSR::HasFocus() {
 }
 
 bool CefRenderWidgetHostViewOSR::IsSurfaceAvailableForCopy() {
-  return delegated_frame_host_->CanCopyFromCompositingSurface();
+  return delegated_frame_host_
+             ? delegated_frame_host_->CanCopyFromCompositingSurface()
+             : false;
 }
 
 void CefRenderWidgetHostViewOSR::Show() {
@@ -380,10 +391,12 @@ void CefRenderWidgetHostViewOSR::Show() {
         base::nullopt /* record_tab_switch_time_request */);
   }
 
+  if (delegated_frame_host_) {
     delegated_frame_host_->AttachToCompositor(compositor_.get());
     delegated_frame_host_->WasShown(
-      GetLocalSurfaceIdAllocation().local_surface_id(), GetViewBounds().size(),
-      base::nullopt);
+        GetLocalSurfaceIdAllocation().local_surface_id(),
+        GetViewBounds().size(), base::nullopt);
+  }
 
   if (!content::GpuDataManagerImpl::GetInstance()->IsGpuCompositingDisabled()) {
     // Start generating frames when we're visible and at the correct size.
@@ -418,9 +431,11 @@ void CefRenderWidgetHostViewOSR::Hide() {
   if (render_widget_host_)
     render_widget_host_->WasHidden();
 
+  if (delegated_frame_host_) {
     delegated_frame_host_->WasHidden(
         content::DelegatedFrameHost::HiddenCause::kOther);
     delegated_frame_host_->DetachFromCompositor();
+  }
 }
 
 bool CefRenderWidgetHostViewOSR::IsShowing() {
@@ -554,7 +569,9 @@ void CefRenderWidgetHostViewOSR::AddDamageRect(uint32_t sequence,
 }
 
 void CefRenderWidgetHostViewOSR::ResetFallbackToFirstNavigationSurface() {
+  if (delegated_frame_host_) {
     delegated_frame_host_->ResetFallbackToFirstNavigationSurface();
+  }
 }
 
 void CefRenderWidgetHostViewOSR::InitAsPopup(
@@ -718,8 +735,10 @@ void CefRenderWidgetHostViewOSR::CopyFromSurface(
     const gfx::Rect& src_rect,
     const gfx::Size& output_size,
     base::OnceCallback<void(const SkBitmap&)> callback) {
+  if (delegated_frame_host_) {
     delegated_frame_host_->CopyFromCompositingSurface(src_rect, output_size,
                                                       std::move(callback));
+  }
 }
 
 void CefRenderWidgetHostViewOSR::GetScreenInfo(content::ScreenInfo* results) {
@@ -894,11 +913,13 @@ CefRenderWidgetHostViewOSR::GetLocalSurfaceIdAllocation() const {
 }
 
 const viz::FrameSinkId& CefRenderWidgetHostViewOSR::GetFrameSinkId() const {
-  return delegated_frame_host_->frame_sink_id();
+  return delegated_frame_host_
+             ? delegated_frame_host_->frame_sink_id()
+             : viz::FrameSinkIdAllocator::InvalidFrameSinkId();
 }
 
 viz::FrameSinkId CefRenderWidgetHostViewOSR::GetRootFrameSinkId() {
-  return compositor_->frame_sink_id();
+  return compositor_ ? compositor_->frame_sink_id() : viz::FrameSinkId();
 }
 
 void CefRenderWidgetHostViewOSR::OnRenderFrameMetadataChangedAfterActivation() {
@@ -1077,10 +1098,12 @@ void CefRenderWidgetHostViewOSR::SendExternalBeginFrame() {
   if (render_widget_host_)
     render_widget_host_->ProgressFlingIfNeeded(frame_time);
 
+  if (compositor_) {
     compositor_->IssueExternalBeginFrame(
         begin_frame_args, /* force= */ true,
         base::BindOnce(&CefRenderWidgetHostViewOSR::OnFrameComplete,
                        weak_ptr_factory_.GetWeakPtr()));
+  }
 
   if (!IsPopupWidget() && popup_host_view_) {
     popup_host_view_->SendExternalBeginFrame();

libcef/browser/osr/render_widget_host_view_osr.h

@@ -264,6 +264,8 @@ class CefRenderWidgetHostViewOSR : public content::RenderWidgetHostViewBase,
   void OnDidUpdateVisualPropertiesComplete(
       const cc::RenderFrameMetadata& metadata);
 
+  void ReleaseCompositor();
+
  private:
   void SetFrameRate();
   bool SetDeviceScaleFactor();