Only commit cookie changes in prerenders after a prerender is shown

chrome/browser/prerender/prerender_contents.h

Index: chrome/browser/prerender/prerender_contents.h
===================================================================
--- chrome/browser/prerender/prerender_contents.h	(revision 269838)
+++ chrome/browser/prerender/prerender_contents.h	(working copy)
@@ -39,6 +39,10 @@
 struct HistoryAddPageArgs;
 }
 
+namespace net {
+class URLRequestContextGetter;
+}
+
 namespace prerender {
 
 class PrerenderHandle;
@@ -46,7 +50,8 @@
 class PrerenderResourceThrottle;
 
 class PrerenderContents : public content::NotificationObserver,
-                          public content::WebContentsObserver {
+                          public content::WebContentsObserver,
+                          public base::SupportsWeakPtr<PrerenderContents> {
  public:
   // PrerenderContents::Create uses the currently registered Factory to create
   // the PrerenderContents. Factory is intended for testing.
@@ -151,7 +156,8 @@
   virtual void StartPrerendering(
       int creator_child_id,
       const gfx::Size& size,
-      content::SessionStorageNamespace* session_storage_namespace);
+      content::SessionStorageNamespace* session_storage_namespace,
+      net::URLRequestContextGetter* request_context);
 
   // Verifies that the prerendering is not using too many resources, and kills
   // it if not.