Allow transitions to WebUI pages which are extension urls (new tab page is the relevant example).

chrome/renderer/extensions/resource_request_policy.h

Index: chrome/renderer/extensions/resource_request_policy.h
===================================================================
--- chrome/renderer/extensions/resource_request_policy.h	(revision 150475)
+++ chrome/renderer/extensions/resource_request_policy.h	(working copy)
@@ -5,6 +5,8 @@
 #ifndef CHROME_RENDERER_EXTENSIONS_RESOURCE_REQUEST_POLICY_H_
 #define CHROME_RENDERER_EXTENSIONS_RESOURCE_REQUEST_POLICY_H_
 
+#include "content/public/common/page_transition_types.h"
+
 class ExtensionSet;
 class GURL;
 
@@ -19,9 +21,12 @@
 class ResourceRequestPolicy {
  public:
   // Returns true if the chrome-extension:// |resource_url| can be requested
-  // from |frame_url|.
+  // from |frame_url|. In some cases this decision is made based upon how
+  // this request was generated. Web triggered transitions are more restrictive
+  // than those triggered through UI.
   static bool CanRequestResource(const GURL& resource_url,
                                  WebKit::WebFrame* frame,
+                                 content::PageTransition transition_type,
                                  const ExtensionSet* loaded_extensions);
   // Returns true if the chrome-extension-resource:// |resource_url| can be
   // requested from |frame_url|.