Fix unload controller.

chrome/browser/ui/unload_controller.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/ui/unload_controller.h"
 
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chrome/browser/chrome_notification_types.h"
@@ skipping 273 matching lines @@
 
 void UnloadController::TabDetachedImpl(content::WebContents* contents) {
   if (is_attempting_to_close_browser_)
     ClearUnloadState(contents, false);
   registrar_.Remove(this,
                     content::NOTIFICATION_WEB_CONTENTS_DISCONNECTED,
                     content::Source<content::WebContents>(contents));
 }
 
 void UnloadController::ProcessPendingTabs() {
+  // Cancel posted/queued ProcessPendingTabs task if there is any.
+  weak_factory_.InvalidateWeakPtrs();
+
   if (!is_attempting_to_close_browser_) {
     // Because we might invoke this after a delay it's possible for the value of
     // is_attempting_to_close_browser_ to have changed since we scheduled the
     // task.
     return;
   }
 
-  if (HasCompletedUnloadProcessing()) {
+  if (HasCompletedUnloadProcessing() && !TabsNeedBeforeUnloadFired()) {
     // We've finished all the unload events and can proceed to close the
     // browser.
     browser_->OnWindowClosing();
     return;
   }
 
   // Process beforeunload tabs first. When that queue is empty, process
   // unload tabs.
   if (!tabs_needing_before_unload_fired_.empty()) {
     content::WebContents* web_contents =
@@ skipping 60 matching lines @@
 }
 
 void UnloadController::ClearUnloadState(content::WebContents* web_contents,
                                         bool process_now) {
   if (is_attempting_to_close_browser_) {
     RemoveFromSet(&tabs_needing_before_unload_fired_, web_contents);
     RemoveFromSet(&tabs_needing_unload_fired_, web_contents);
     if (process_now) {
       ProcessPendingTabs();
     } else {
+      // Do not post a new task if there is already any.
+      if (weak_factory_.HasWeakPtrs())
+        return;
       base::ThreadTaskRunnerHandle::Get()->PostTask(
           FROM_HERE, base::Bind(&UnloadController::ProcessPendingTabs,
                                 weak_factory_.GetWeakPtr()));
     }
   }
 }
 
 }  // namespace chrome