Fix RenderWidgetHostViewAura as observer of CompositorVSyncManager

content/browser/renderer_host/render_widget_host_view_aura.cc

 // Copyright (c) 2012 The Chromium 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 "content/browser/renderer_host/render_widget_host_view_aura.h"
 
 #include "base/auto_reset.h"
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/callback_helpers.h"
@@ skipping 49 matching lines @@
 #include "ui/aura/client/window_tree_client.h"
 #include "ui/aura/env.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_observer.h"
 #include "ui/aura/window_tracker.h"
 #include "ui/base/clipboard/scoped_clipboard_writer.h"
 #include "ui/base/hit_test.h"
 #include "ui/base/ime/input_method.h"
 #include "ui/base/ui_base_types.h"
+#include "ui/compositor/compositor_vsync_manager.h"
 #include "ui/compositor/layer.h"
 #include "ui/events/event.h"
 #include "ui/events/event_utils.h"
 #include "ui/events/gestures/gesture_recognizer.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/display.h"
 #include "ui/gfx/rect_conversions.h"
 #include "ui/gfx/screen.h"
 #include "ui/gfx/size_conversions.h"
 #include "ui/gfx/skia_util.h"
@@ skipping 3444 matching lines @@
 
 #if defined(OS_WIN)
   // The parent may have changed here. Ensure that the legacy window is
   // reparented accordingly.
   if (legacy_render_widget_host_HWND_)
     legacy_render_widget_host_HWND_->UpdateParent(
         reinterpret_cast<HWND>(GetNativeViewId()));
 #endif
 
   ui::Compositor* compositor = GetCompositor();
-  if (compositor)
-    compositor->vsync_manager()->AddObserver(this);
+  if (compositor) {

[piman, 2014/02/13 02:06:45]

nit: maybe DCHECK(!vsync_manager_.get()) here, and in the destructor?

+    vsync_manager_ = compositor->vsync_manager();
+    vsync_manager_->AddObserver(this);
+  }
 }
 
 void RenderWidgetHostViewAura::RemovingFromRootWindow() {
   aura::client::CursorClient* cursor_client =
       aura::client::GetCursorClient(window_->GetRootWindow());
   if (cursor_client)
     cursor_client->RemoveObserver(this);
 
   DetachFromInputMethod();
 
   window_->GetDispatcher()->RemoveRootWindowObserver(this);
   ui::Compositor* compositor = GetCompositor();
   if (current_surface_.get()) {
     // We can't get notification for commits after this point, which would
     // guarantee that the compositor isn't using an old texture any more, so
     // instead we force the layer to stop using any external resources which
     // synchronizes with the compositor thread, and makes it safe to run the
     // callback.
     window_->layer()->SetShowPaintedContent();
   }
   RunOnCommitCallbacks();
   resize_lock_.reset();
   host_->WasResized();
 
-  if (compositor) {
-    if (compositor->HasObserver(this))
-      compositor->RemoveObserver(this);
-    compositor->vsync_manager()->RemoveObserver(this);
-  }
+  if (compositor && compositor->HasObserver(this))
+    compositor->RemoveObserver(this);
 
 #if defined(OS_WIN)
   // Update the legacy window's parent temporarily to the desktop window. It
   // will eventually get reparented to the right root.
   if (legacy_render_widget_host_HWND_)
     legacy_render_widget_host_HWND_->UpdateParent(::GetDesktopWindow());
 #endif
+
+  if (vsync_manager_) {
+    vsync_manager_->RemoveObserver(this);
+    vsync_manager_ = NULL;
+  }
 }
 
 ui::Compositor* RenderWidgetHostViewAura::GetCompositor() const {
   aura::WindowEventDispatcher* dispatcher = window_->GetDispatcher();
   return dispatcher ? dispatcher->host()->compositor() : NULL;
 }
 
 void RenderWidgetHostViewAura::DetachFromInputMethod() {
   ui::InputMethod* input_method = GetInputMethod();
   if (input_method && input_method->GetTextInputClient() == this)
@@ skipping 18 matching lines @@
     RenderWidgetHost* widget) {
   return new RenderWidgetHostViewAura(widget);
 }
 
 // static
 void RenderWidgetHostViewPort::GetDefaultScreenInfo(WebScreenInfo* results) {
   GetScreenInfoForWindow(results, NULL);
 }
 
 }  // namespace content