Stop disabling force_compositing_mode for background RenderViews.

chrome/browser/tab_contents/background_contents.cc

Index: chrome/browser/tab_contents/background_contents.cc
diff --git a/chrome/browser/tab_contents/background_contents.cc b/chrome/browser/tab_contents/background_contents.cc
index 9420402e6614422bbd1554fc05fd12a153e800c5..20902f3772e101b8eea9d12387901652c41653da 100644
--- a/chrome/browser/tab_contents/background_contents.cc
+++ b/chrome/browser/tab_contents/background_contents.cc
@@ -123,6 +123,12 @@ void BackgroundContents::AddNewContents(WebContents* source,
       new_contents, disposition, initial_pos, user_gesture, was_blocked);
 }
 
+bool BackgroundContents::IsNeverVisible(content::WebContents* web_contents) {
+  DCHECK_EQ(extensions::VIEW_TYPE_BACKGROUND_CONTENTS,
+            extensions::GetViewType(web_contents));
+  return true;
+}
+
 void BackgroundContents::RenderProcessGone(base::TerminationStatus status) {
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_BACKGROUND_CONTENTS_TERMINATED,