Stop disabling force_compositing_mode for background RenderViews.

content/public/browser/content_browser_client.h

Index: content/public/browser/content_browser_client.h
diff --git a/content/public/browser/content_browser_client.h b/content/public/browser/content_browser_client.h
index 01c2eb93e039131faa11d35a60ab5688134bb724..ae90c0ff0eb930b5195c53a10fdb35906b37e961 100644
--- a/content/public/browser/content_browser_client.h
+++ b/content/public/browser/content_browser_client.h
@@ -520,6 +520,9 @@ class CONTENT_EXPORT ContentBrowserClient {
   // Returns true if fast shutdown is possible.
   virtual bool IsFastShutdownPossible();
 
+  // Returns true if the view runs in the background and is never visible.
+  virtual bool IsRenderViewHostForBackground(RenderViewHost* render_view_host);

[jam, 2014/04/10 20:27:48]

nit: content doesn't know about "background" concept, that's an extensions
feature. so maybe call this IsRenderViewHostNeverVisible or something similar?

[danakj, 2014/04/10 20:37:12]

Done.

+
   // Called by WebContents to override the WebKit preferences that are used by
   // the renderer. The content layer will add its own settings, and then it's up
   // to the embedder to update it if it wants.