content: convert zoom notifications to observer usage

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 194 matching lines @@
 ////////////////////////////////////////////////////////////////////////////////
 // WrenchMenuModel
 
 WrenchMenuModel::WrenchMenuModel(ui::AcceleratorProvider* provider,
                                  Browser* browser,
                                  bool is_new_menu,
                                  bool supports_new_separators)
     : ALLOW_THIS_IN_INITIALIZER_LIST(ui::SimpleMenuModel(this)),
       provider_(provider),
       browser_(browser),
-      tab_strip_model_(browser_->tab_strip_model()) {
+      tab_strip_model_(browser_->tab_strip_model()),
+      zoom_callback_(base::Bind(&WrenchMenuModel::OnZoomLevelChanged,
+                                base::Unretained(this))) {
   Build(is_new_menu, supports_new_separators);
   UpdateZoomControls();
 
+  HostZoomMap::GetForBrowserContext(
+      browser->profile())->AddZoomLevelChangedCallback(zoom_callback_);
+
   tab_strip_model_->AddObserver(this);
 
-  registrar_.Add(
-      this, content::NOTIFICATION_ZOOM_LEVEL_CHANGED,
-      content::Source<HostZoomMap>(
-          HostZoomMap::GetForBrowserContext(browser_->profile())));
   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 172 matching lines @@
 void WrenchMenuModel::TabStripModelDeleted() {
   // During views shutdown, the tabstrip model/browser is deleted first, while
   // it is the opposite in gtk land.
   tab_strip_model_->RemoveObserver(this);
   tab_strip_model_ = NULL;
 }
 
 void WrenchMenuModel::Observe(int type,
                               const content::NotificationSource& source,
                               const content::NotificationDetails& details) {
-  switch (type) {
-    case content::NOTIFICATION_ZOOM_LEVEL_CHANGED:
-    case content::NOTIFICATION_NAV_ENTRY_COMMITTED:
-      UpdateZoomControls();
-      break;
-    default:
-      NOTREACHED();
-  }
+  DCHECK(type == content::NOTIFICATION_NAV_ENTRY_COMMITTED);
+  UpdateZoomControls();
 }
 
 // For testing.
 WrenchMenuModel::WrenchMenuModel()
     : ALLOW_THIS_IN_INITIALIZER_LIST(ui::SimpleMenuModel(this)),
       provider_(NULL),
       browser_(NULL),
       tab_strip_model_(NULL) {
 }
 
@@ skipping 248 matching lines @@
   bool enable_decrement = false;
   int zoom_percent = 100;
   if (browser_->tab_strip_model()->GetActiveWebContents()) {
     zoom_percent =
         browser_->tab_strip_model()->GetActiveWebContents()->GetZoomPercent(
             &enable_increment, &enable_decrement);
   }
   zoom_label_ = l10n_util::GetStringFUTF16(
       IDS_ZOOM_PERCENT, base::IntToString16(zoom_percent));
 }
+
+void WrenchMenuModel::OnZoomLevelChanged(const std::string& host) {
+  UpdateZoomControls();
+}