Remove RenderWidget::SetBackground, change IPC to pass a bool.

content/renderer/render_view_impl.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_RENDERER_RENDER_VIEW_IMPL_H_
 #define CONTENT_RENDERER_RENDER_VIEW_IMPL_H_
 
 #include <deque>
 #include <map>
 #include <set>
@@ skipping 724 matching lines @@
   void OnMediaPlayerActionAt(const gfx::Point& location,
                              const blink::WebMediaPlayerAction& action);
   void OnPluginActionAt(const gfx::Point& location,
                         const blink::WebPluginAction& action);
   void OnMoveOrResizeStarted();
   void OnPostMessageEvent(const ViewMsg_PostMessage_Params& params);
   void OnReleaseDisambiguationPopupBitmap(const cc::SharedBitmapId& id);
   void OnResetPageEncodingToDefault();
   void OnSetAccessibilityMode(AccessibilityMode new_mode);
   void OnSetActive(bool active);
-  void OnSetBackground(const SkBitmap& background);
+  void OnSetBackgroundOpaque(bool opaque);
   void OnExitFullscreen();
   void OnSetHistoryLengthAndPrune(int history_length, int32 minimum_page_id);
   void OnSetInitialFocus(bool reverse);
   void OnSetPageEncoding(const std::string& encoding_name);
   void OnSetRendererPrefs(const RendererPreferences& renderer_prefs);
   void OnSetWebUIProperty(const std::string& name, const std::string& value);
   void OnSetZoomLevel(double zoom_level);
   void OnSetZoomLevelForLoadingURL(const GURL& url, double zoom_level);
   void OnStop();
   void OnStopFinding(StopFindAction action);
@@ skipping 456 matching lines @@
   // use the Observer interface to filter IPC messages and receive frame change
   // notifications.
   // ---------------------------------------------------------------------------
 
   DISALLOW_COPY_AND_ASSIGN(RenderViewImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_VIEW_IMPL_H_