Add base::RunLoop and update ui_test_utils to use it to reduce flakiness

chrome/browser/extensions/extension_browsertest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/extension_browsertest.h"
 
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/file_path.h"
@@ skipping 121 matching lines @@
     CHECK(service->AllowFileAccess(extension));
 
     if (!fileaccess_enabled) {
       service->SetAllowFileAccess(extension, fileaccess_enabled);
       load_signal.Wait();
       extension = service->GetExtensionById(extension_id, false);
       CHECK(extension) << extension_id << " not found after reloading.";
     }
   }
 
+  // After chrome::NOTIFICATION_EXTENSION_LOADED there are still remaining tasks

[Paweł Hajdan Jr., 2012/06/18 15:56:25]

Have you checked all tests where we wait for NOTIFICATION_EXTENSION_LOADED? Just
checking.

[jbates, 2012/06/18 23:14:03]

Removed to see if reposting Quit task is enough.

+  // that need to complete for extensions to be in a settled load state.
+  ui_test_utils::RunAllPendingInMessageLoop();
+
   if (!WaitForExtensionViewsToLoad())
     return NULL;
 
   return extension;
 }
 
 const Extension* ExtensionBrowserTest::LoadExtension(const FilePath& path) {
   return LoadExtensionWithOptions(path, false, true);
 }
 
@@ skipping 447 matching lines @@
     case content::NOTIFICATION_LOAD_STOP:
       VLOG(1) << "Got LOAD_STOP notification.";
       MessageLoopForUI::current()->Quit();
       break;
 
     default:
       NOTREACHED();
       break;
   }
 }