Convert zoom callbacks to use CallbackRegistry

chrome/browser/ui/toolbar/wrench_menu_model.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/toolbar/wrench_menu_model.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/command_line.h"
@@ skipping 215 matching lines @@
 
 ////////////////////////////////////////////////////////////////////////////////
 // WrenchMenuModel
 
 WrenchMenuModel::WrenchMenuModel(ui::AcceleratorProvider* provider,
                                  Browser* browser,
                                  bool is_new_menu)
     : ui::SimpleMenuModel(this),
       provider_(provider),
       browser_(browser),
-      tab_strip_model_(browser_->tab_strip_model()),
-      zoom_callback_(base::Bind(&WrenchMenuModel::OnZoomLevelChanged,
-                                base::Unretained(this))) {
+      tab_strip_model_(browser_->tab_strip_model()) {
   Build(is_new_menu);
   UpdateZoomControls();
 
-  HostZoomMap::GetForBrowserContext(
-      browser->profile())->AddZoomLevelChangedCallback(zoom_callback_);
+  zoom_subscription_ = HostZoomMap::GetForBrowserContext(
+      browser->profile())->AddZoomLevelChangedCallback(
+          base::Bind(&WrenchMenuModel::OnZoomLevelChanged,
+                     base::Unretained(this)));
 
   tab_strip_model_->AddObserver(this);
 
   registrar_.Add(this, content::NOTIFICATION_NAV_ENTRY_COMMITTED,
                  content::NotificationService::AllSources());
 }
 
 WrenchMenuModel::~WrenchMenuModel() {
   if (tab_strip_model_)
     tab_strip_model_->RemoveObserver(this);
-
-  if (browser()) {
-    HostZoomMap::GetForBrowserContext(
-        browser()->profile())->RemoveZoomLevelChangedCallback(zoom_callback_);
-  }
 }
 
 bool WrenchMenuModel::DoesCommandIdDismissMenu(int command_id) const {
   return command_id != IDC_ZOOM_MINUS && command_id != IDC_ZOOM_PLUS;
 }
 
 bool WrenchMenuModel::IsItemForCommandIdDynamic(int command_id) const {
   return command_id == IDC_ZOOM_PERCENT_DISPLAY ||
 #if defined(OS_MACOSX)
          command_id == IDC_FULLSCREEN ||
@@ skipping 490 matching lines @@
             &enable_increment, &enable_decrement);
   }
   zoom_label_ = l10n_util::GetStringFUTF16(
       IDS_ZOOM_PERCENT, base::IntToString16(zoom_percent));
 }
 
 void WrenchMenuModel::OnZoomLevelChanged(
     const content::HostZoomMap::ZoomLevelChange& change) {
   UpdateZoomControls();
 }