Unbreak tabs.onRemove extension API in face of fast tab closure

chrome/browser/ui/tab_contents/core_tab_helper.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/tab_contents/core_tab_helper.h"
 
 #include "base/metrics/histogram.h"
 #include "chrome/browser/renderer_host/web_cache_manager.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
 #include "net/base/load_states.h"
 #include "grit/generated_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 
 using content::WebContents;
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(CoreTabHelper);
 
 CoreTabHelper::CoreTabHelper(WebContents* web_contents)
     : content::WebContentsObserver(web_contents),
-      delegate_(NULL) {
+      delegate_(NULL),
+      detached_as_part_of_unload_(false) {
 }
 
 CoreTabHelper::~CoreTabHelper() {
 }
 
 string16 CoreTabHelper::GetDefaultTitle() {
   return l10n_util::GetStringUTF16(IDS_DEFAULT_TAB_TITLE);
 }
 
 string16 CoreTabHelper::GetStatusText() const {
@@ skipping 45 matching lines @@
                                         web_contents()->GetLoadStateHost());
     // Ignore net::LOAD_STATE_READING_RESPONSE and net::LOAD_STATE_IDLE
     case net::LOAD_STATE_IDLE:
     case net::LOAD_STATE_READING_RESPONSE:
       break;
   }
 
   return string16();
 }
 
+bool CoreTabHelper::GetWebContentsDetachedToClose() const {
+  return detached_as_part_of_unload_;
+}
+
 void CoreTabHelper::OnCloseStarted() {
   if (close_start_time_.is_null())
     close_start_time_ = base::TimeTicks::Now();
 }
 
 void CoreTabHelper::OnCloseCanceled() {
   close_start_time_ = base::TimeTicks();
   before_unload_end_time_ = base::TimeTicks();
   unload_detached_start_time_ = base::TimeTicks();
 }
 
 void CoreTabHelper::OnUnloadStarted() {
   before_unload_end_time_ = base::TimeTicks::Now();
 }
 
+void CoreTabHelper::OnUnloadAboutToDetach() {
+  detached_as_part_of_unload_ = true;
+}
+
 void CoreTabHelper::OnUnloadDetachedStarted() {
   if (unload_detached_start_time_.is_null())
     unload_detached_start_time_ = base::TimeTicks::Now();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // WebContentsObserver overrides
 
 void CoreTabHelper::WasShown() {
   WebCacheManager::GetInstance()->ObserveActivity(
@@ skipping 19 matching lines @@
   }
 }
 
 void CoreTabHelper::BeforeUnloadFired(const base::TimeTicks& proceed_time) {
   before_unload_end_time_ = proceed_time;
 }
 
 void CoreTabHelper::BeforeUnloadDialogCancelled() {
   OnCloseCanceled();
 }