Use the NTP background color instead of white when there is no other info.

chrome/browser/ui/views/frame/contents_web_view.h

 // Copyright 2014 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 CHROME_BROWSER_UI_VIEWS_FRAME_CONTENTS_WEB_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_FRAME_CONTENTS_WEB_VIEW_H_
 
 #include <memory>
 
 #include "base/compiler_specific.h"
@@ skipping 20 matching lines @@
   // Sets the status bubble, which should be repositioned every time
   // this view changes visible bounds.
   void SetStatusBubble(StatusBubbleViews* status_bubble);
 
   // WebView overrides:
   bool GetNeedsNotificationWhenVisibleBoundsChange() const override;
   void OnVisibleBoundsChanged() override;
   void ViewHierarchyChanged(
       const ViewHierarchyChangedDetails& details) override;
   void OnThemeChanged() override;
+  void RenderViewReady() override;
 
   // ui::LayerOwnerDelegate overrides:
   void OnLayerRecreated(ui::Layer* old_layer, ui::Layer* new_layer) override;
 
   // WebContentsCloseHandlerDelegate overrides:
   void CloneWebContentsLayer() override;
   void DestroyClonedLayer() override;
 
  private:
   StatusBubbleViews* status_bubble_;
 
   std::unique_ptr<ui::LayerTreeOwner> cloned_layer_tree_;
 
   DISALLOW_COPY_AND_ASSIGN(ContentsWebView);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_FRAME_CONTENTS_WEB_VIEW_H_