Stop disabling force_compositing_mode for background RenderViews.

chrome/browser/tab_contents/background_contents.h

 // Copyright (c) 2011 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_TAB_CONTENTS_BACKGROUND_CONTENTS_H_
 #define CHROME_BROWSER_TAB_CONTENTS_BACKGROUND_CONTENTS_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 47 matching lines @@
   virtual void CloseContents(content::WebContents* source) OVERRIDE;
   virtual bool ShouldSuppressDialogs() OVERRIDE;
   virtual void DidNavigateMainFramePostCommit(
       content::WebContents* tab) OVERRIDE;
   virtual void AddNewContents(content::WebContents* source,
                               content::WebContents* new_contents,
                               WindowOpenDisposition disposition,
                               const gfx::Rect& initial_pos,
                               bool user_gesture,
                               bool* was_blocked) OVERRIDE;
+  virtual bool IsWebContentsNeverVisible(content::WebContents* web_contents)
+      OVERRIDE;

[jam, 2014/04/14 22:43:01]

nit: don't start a line with OVERRIDE. see recent chromium-dev discussion. i
think we're waiting on a new version of clang format which fixes this

[danakj, 2014/04/14 22:47:30]

Yup. Will fix.

 
   // content::WebContentsObserver implementation:
   virtual void RenderProcessGone(base::TerminationStatus status) OVERRIDE;
 
   // content::NotificationObserver
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
  protected:
@@ skipping 17 matching lines @@
   BackgroundContents* contents;
 
   // The name of the parent frame for these contents.
   const base::string16& frame_name;
 
   // The ID of the parent application (if any).
   const base::string16& application_id;
 };
 
 #endif  // CHROME_BROWSER_TAB_CONTENTS_BACKGROUND_CONTENTS_H_