[content] Fix background color update handling in RWHVAura.

content/browser/renderer_host/render_widget_host_view_aura.h

 // 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.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_AURA_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_AURA_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 447 matching lines @@
   // Used to set the |popup_child_host_view_| on the |popup_parent_host_view_|
   // and to notify the |event_handler_|.
   void SetPopupChild(RenderWidgetHostViewAura* popup_child_host_view);
 
   // Forwards a mouse event to this view's parent window delegate.
   void ForwardMouseEventToParent(ui::MouseEvent* event);
 
   // Adds/Removes frame observer based on state.
   void UpdateNeedsBeginFramesInternal();
 
+  // Applies background color without notifying the RenderWidget about
+  // opaqueness changes.
+  void UpdateBackgroundColorFromRenderer(SkColor color);
+
   // The model object.
   RenderWidgetHostImpl* const host_;
 
   aura::Window* window_;
 
   std::unique_ptr<DelegatedFrameHostClient> delegated_frame_host_client_;
   // NOTE: this may be null.
   std::unique_ptr<DelegatedFrameHost> delegated_frame_host_;
 
   std::unique_ptr<WindowObserver> window_observer_;
@@ skipping 101 matching lines @@
 
   // The routing and process IDs for the last RenderWidgetHost which had a
   // TextInputState of non-NONE.
   int32_t last_active_widget_process_id_;
   int32_t last_active_widget_routing_id_;
 
   // While this is a ui::EventHandler for targetting, |event_handler_| actually
   // provides an implementation, and directs events to |host_|.
   std::unique_ptr<RenderWidgetHostViewEventHandler> event_handler_;
 
+  // Body background color of the underlying document.
+  SkColor cached_background_color_;
+
   base::WeakPtrFactory<RenderWidgetHostViewAura> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewAura);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_AURA_H_