content: convert zoom notifications to observer usage

chrome/browser/ui/views/wrench_menu.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/views/wrench_menu.h"
 
 #include <algorithm>
 #include <cmath>
 #include <set>
 
@@ skipping 462 matching lines @@
 
 // ZoomView --------------------------------------------------------------------
 
 // Padding between the increment buttons and the reset button.
 static const int kZoomPadding = 6;
 static const int kTouchZoomPadding = 14;
 
 // ZoomView contains the various zoom controls: two buttons to increase/decrease
 // the zoom, a label showing the current zoom percent, and a button to go
 // full-screen.
-class WrenchMenu::ZoomView : public WrenchMenuView,
-                             public content::NotificationObserver {
+class WrenchMenu::ZoomView : public WrenchMenuView {
  public:
   ZoomView(WrenchMenu* menu,
            MenuModel* menu_model,
            int decrement_index,
            int increment_index,
            int fullscreen_index)
       : WrenchMenuView(menu, menu_model),
         fullscreen_index_(fullscreen_index),
+        zoom_callback_(base::Bind(&WrenchMenu::ZoomView::OnZoomLevelChanged,
+                                  base::Unretained(this))),
         increment_button_(NULL),
         zoom_label_(NULL),
         decrement_button_(NULL),
         fullscreen_button_(NULL),
         zoom_label_width_(0) {
+    HostZoomMap::GetForBrowserContext(
+        menu_->browser_->profile())->AddZoomLevelChangedCallback(
+            zoom_callback_);
+
     decrement_button_ = CreateButtonWithAccName(
         IDS_ZOOM_MINUS2, MenuButtonBackground::LEFT_BUTTON, decrement_index,
         NULL, IDS_ACCNAME_ZOOM_MINUS2);
 
     zoom_label_ = new Label(
         l10n_util::GetStringFUTF16Int(IDS_ZOOM_PERCENT, 100));
     zoom_label_->SetAutoColorReadabilityEnabled(false);
     zoom_label_->SetHorizontalAlignment(gfx::ALIGN_RIGHT);
 
     MenuButtonBackground* center_bg = new MenuButtonBackground(
@@ skipping 40 matching lines @@
         0, horizontal_padding, 0, horizontal_padding));
     fullscreen_button_->set_background(
         new MenuButtonBackground(MenuButtonBackground::SINGLE_BUTTON,
                                  menu_->use_new_menu()));
     fullscreen_button_->SetAccessibleName(
         GetAccessibleNameForWrenchMenuItem(
             menu_model, fullscreen_index, IDS_ACCNAME_FULLSCREEN));
     AddChildView(fullscreen_button_);
 
     UpdateZoomControls();
+  }
 
-    registrar_.Add(
-        this, content::NOTIFICATION_ZOOM_LEVEL_CHANGED,
-        content::Source<HostZoomMap>(
-            HostZoomMap::GetForBrowserContext(menu->browser_->profile())));
+  ~ZoomView() {
+    HostZoomMap::GetForBrowserContext(
+        menu_->browser_->profile())->RemoveZoomLevelChangedCallback(
+            zoom_callback_);
   }
 
   // Overridden from View.
   virtual gfx::Size GetPreferredSize() OVERRIDE {
     // The increment/decrement button are forced to the same width.
     int button_width = std::max(increment_button_->GetPreferredSize().width(),
                                 decrement_button_->GetPreferredSize().width());
     int zoom_padding = menu_->use_new_menu() ? kTouchZoomPadding : kZoomPadding;
     int fullscreen_width = fullscreen_button_->GetPreferredSize().width() +
                            zoom_padding;
@@ skipping 33 matching lines @@
   virtual void ButtonPressed(views::Button* sender,
                              const ui::Event& event) OVERRIDE {
     if (sender->tag() == fullscreen_index_) {
       menu_->CancelAndEvaluate(menu_model_, sender->tag());
     } else {
       // Zoom buttons don't close the menu.
       menu_model_->ActivatedAt(sender->tag());
     }
   }
 
-  // Overridden from content::NotificationObserver.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE {
-    DCHECK_EQ(content::NOTIFICATION_ZOOM_LEVEL_CHANGED, type);
+ private:
+  void OnZoomLevelChanged(const std::string& host) {
     UpdateZoomControls();
   }
 
- private:
   void UpdateZoomControls() {
     bool enable_increment = false;
     bool enable_decrement = false;
     WebContents* selected_tab =
         menu_->browser_->tab_strip_model()->GetActiveWebContents();
     int zoom = 100;
     if (selected_tab)
       zoom = selected_tab->GetZoomPercent(&enable_increment, &enable_decrement);
     increment_button_->SetEnabled(enable_increment);
     decrement_button_->SetEnabled(enable_decrement);
@@ skipping 27 matching lines @@
       max_w = font.GetStringWidth(
           l10n_util::GetStringFUTF16Int(IDS_ZOOM_PERCENT, 100));
     }
 
     return max_w + border_width;
   }
 
   // Index of the fullscreen menu item in the model.
   const int fullscreen_index_;
 
+  content::HostZoomMap::ZoomLevelChangedCallback zoom_callback_;
   content::NotificationRegistrar registrar_;
 
   // Button for incrementing the zoom.
   TextButton* increment_button_;
 
   // Label showing zoom as a percent.
   Label* zoom_label_;
 
   // Button for decrementing the zoom.
   TextButton* decrement_button_;
@@ skipping 448 matching lines @@
   bookmark_menu_delegate_.reset(
       new BookmarkMenuDelegate(browser_,
                                browser_,
                                parent,
                                first_bookmark_command_id_));
   bookmark_menu_delegate_->Init(
       this, bookmark_menu_, model->bookmark_bar_node(), 0,
       BookmarkMenuDelegate::SHOW_PERMANENT_FOLDERS,
       bookmark_utils::LAUNCH_WRENCH_MENU);
 }