Create content::WebContentsDestroyedWatcher, use it in many tests.

content/public/test/browser_test_utils.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 "content/public/test/browser_test_utils.h"
 
 #include "base/command_line.h"
 #include "base/json/json_reader.h"
 #include "base/path_service.h"
 #include "base/process/kill.h"
@@ skipping 564 matching lines @@
       std::find(expected_titles_.begin(),
                 expected_titles_.end(),
                 web_contents()->GetTitle());
   if (it == expected_titles_.end())
     return;
 
   observed_title_ = *it;
   message_loop_runner_->Quit();
 }
 
+WebContentsDestroyedWatcher::WebContentsDestroyedWatcher(
+    WebContents* web_contents)
+    : WebContentsObserver(web_contents),
+      message_loop_runner_(new MessageLoopRunner) {
+  EXPECT_TRUE(web_contents != NULL);
+}
+
+WebContentsDestroyedWatcher::~WebContentsDestroyedWatcher() {
+}
+
+void WebContentsDestroyedWatcher::Wait() {
+  message_loop_runner_->Run();
+}
+
+void WebContentsDestroyedWatcher::WebContentsDestroyed(
+    WebContents* web_contents) {
+  message_loop_runner_->Quit();
+}
+
 DOMMessageQueue::DOMMessageQueue() : waiting_for_message_(false) {
   registrar_.Add(this, NOTIFICATION_DOM_OPERATION_RESPONSE,
                  NotificationService::AllSources());
 }
 
 DOMMessageQueue::~DOMMessageQueue() {}
 
 void DOMMessageQueue::Observe(int type,
                               const NotificationSource& source,
                               const NotificationDetails& details) {
@@ skipping 20 matching lines @@
   // The queue should not be empty, unless we were quit because of a timeout.
   if (message_queue_.empty())
     return false;
   if (message)
     *message = message_queue_.front();
   message_queue_.pop();
   return true;
 }
 
 }  // namespace content