[content] Fix background color update handling in RWHVAura.

content/browser/renderer_host/render_widget_host_view_mac.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_MAC_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_
 
 #import <Cocoa/Cocoa.h>
 #include <IOSurface/IOSurface.h>
 #include <stddef.h>
@@ skipping 259 matching lines @@
   void WasOccluded() override;
   gfx::Rect GetViewBounds() const override;
   void SetShowingContextMenu(bool showing) override;
   void SetActive(bool active) override;
   void ShowDefinitionForSelection() override;
   bool SupportsSpeech() const override;
   void SpeakSelection() override;
   bool IsSpeaking() const override;
   void StopSpeaking() override;
   void SetBackgroundColor(SkColor color) override;
+  SkColor background_color() const override;
   void SetNeedsBeginFrames(bool needs_begin_frames) override;
 
   // Implementation of RenderWidgetHostViewBase.
   void InitAsPopup(RenderWidgetHostView* parent_host_view,
                    const gfx::Rect& pos) override;
   void InitAsFullscreen(RenderWidgetHostView* reference_host_view) override;
   void Focus() override;
   void UpdateCursor(const WebCursor& cursor) override;
   void SetIsLoading(bool is_loading) override;
   void RenderProcessGone(base::TerminationStatus status,
@@ skipping 255 matching lines @@
   // to SendVSyncParametersToRenderer(), and refreshed regularly thereafter.
   base::TimeTicks vsync_timebase_;
   base::TimeDelta vsync_interval_;
 
   // Whether a request for begin frames has been issued.
   bool needs_begin_frames_;
 
   // Whether a request to flush input has been issued.
   bool needs_flush_input_;
 
+  // The background color of the widget.
+  SkColor background_color_;
+
   // Factory used to safely scope delayed calls to ShutdownHost().
   base::WeakPtrFactory<RenderWidgetHostViewMac> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewMac);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_