Set an initial background for RenderFrameHosts during commit.

content/browser/web_contents/web_contents_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_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_
 #define CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_
 
 #include <stdint.h>
 
 #include <functional>
@@ skipping 677 matching lines @@
       bool proceed,
       const base::TimeTicks& proceed_time,
       bool* proceed_to_fire_unload) override;
   void RenderProcessGoneFromRenderManager(
       RenderViewHost* render_view_host) override;
   void UpdateRenderViewSizeForRenderManager() override;
   void CancelModalDialogsForRenderManager() override;
   void NotifySwappedFromRenderManager(RenderFrameHost* old_host,
                                       RenderFrameHost* new_host,
                                       bool is_main_frame) override;
+  void NotifyInitialBackground(SkColor old_background,
+                               RenderFrameHost* new_host) override;
   void NotifyMainFrameSwappedFromRenderManager(
       RenderViewHost* old_host,
       RenderViewHost* new_host) override;
   NavigationControllerImpl& GetControllerForRenderManager() override;
   NavigationEntry* GetLastCommittedNavigationEntryForRenderManager() override;
   bool FocusLocationBarByDefault() override;
   void SetFocusToLocationBar(bool select_all) override;
   bool IsHidden() override;
   int GetOuterDelegateFrameTreeNodeId() override;
   RenderWidgetHostImpl* GetFullscreenRenderWidgetHost() const override;
@@ skipping 829 matching lines @@
   // Adds/removes a callback called on creation of each new WebContents.
   static void AddCreatedCallbackForTesting(const CreatedCallback& callback);
   static void RemoveCreatedCallbackForTesting(const CreatedCallback& callback);
 
   DISALLOW_COPY_AND_ASSIGN(FriendZone);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_