Only commit cookie changes in prerenders after a prerender is shown

chrome/browser/extensions/activity_log/activity_log_browsertest.cc

Index: chrome/browser/extensions/activity_log/activity_log_browsertest.cc
===================================================================
--- chrome/browser/extensions/activity_log/activity_log_browsertest.cc	(revision 269838)
+++ chrome/browser/extensions/activity_log/activity_log_browsertest.cc	(working copy)
@@ -12,7 +12,10 @@
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/test/base/ui_test_utils.h"
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_service.h"
+#include "content/public/browser/storage_partition.h"
 #include "content/public/test/browser_test_utils.h"
 #include "net/dns/mock_host_resolver.h"
 #include "net/test/embedded_test_server/embedded_test_server.h"
@@ -99,6 +102,13 @@
       "http://www.google.com.bo:%d/test.html",
       port));
 
+  if (!prerender_manager->cookie_store_loaded()) {
+    base::RunLoop loop;
+    prerender_manager->set_on_cookie_store_loaded_cb_for_testing(
+        loop.QuitClosure());
+    loop.Run();
+  }
+
   const gfx::Size kSize(640, 480);
   scoped_ptr<prerender::PrerenderHandle> prerender_handle(
       prerender_manager->AddPrerenderFromLocalPredictor(