Allow to have a transparent UA dependent background.

content/browser/renderer_host/render_widget_host_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_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_IMPL_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 354 matching lines @@
   }
 
   // Whether forwarded WebInputEvents should be dropped.
   bool ShouldDropInputEvents() const;
 
   bool has_touch_handler() const { return has_touch_handler_; }
 
   // Set the RenderView background transparency.
   void SetBackgroundOpaque(bool opaque);
 
+  // Set the RenderView background color.
+  void SetBackgroundColor(SkColor color);
+
   // Notifies the renderer that the next key event is bound to one or more
   // pre-defined edit commands
   void SetEditCommandsForNextKeyEvent(
       const std::vector<EditCommand>& commands);
 
   // Executes the edit command.
   void ExecuteEditCommand(const std::string& command,
                           const std::string& value);
 
   // Tells the renderer to scroll the currently focused node into rect only if
@@ skipping 457 matching lines @@
   scoped_ptr<base::ElapsedTimer> mouse_wheel_coalesce_timer_;
 
   base::WeakPtrFactory<RenderWidgetHostImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_IMPL_H_