Split ExtensionTestObserver and move to //extensions.

chrome/browser/extensions/process_manager_browsertest.cc

 // Copyright 2013 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 <stddef.h>
 
 #include <memory>
 #include <utility>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/run_loop.h"
+#include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/extensions/browser_action_test_util.h"
 #include "chrome/browser/extensions/extension_browsertest.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/test_extension_dir.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/extensions/extension_process_policy.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/ui_test_utils.h"
 #include "content/public/browser/child_process_security_policy.h"
@@ skipping 926 matching lines @@
   EXPECT_TRUE(ExecuteScriptAndExtractBool(
       popup, "window.domAutomationController.send(!!window.opener)",
       &is_opener_defined));
   EXPECT_TRUE(is_opener_defined);
 
   // Verify that postMessage to window.opener works.
   VerifyPostMessageToOpener(popup->GetMainFrame(), extension_frame);
 }
 
 }  // namespace extensions