Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/ui/cocoa/browser_window_cocoa.mm

 // 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/cocoa/browser_window_cocoa.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/mac/mac_util.h"
@@ skipping 596 matching lines @@
   // BrowserWindow object.
   FindBarBridge* bridge = new FindBarBridge();
   AddFindBar(bridge->find_bar_cocoa_controller());
   return bridge;
 }
 
 bool BrowserWindowCocoa::GetConstrainedWindowTopY(int* top_y) {
   return false;
 }
 
-void BrowserWindowCocoa::Observe(int type,
-                                 const content::NotificationSource& source,
-                                 const content::NotificationDetails& details) {
-  switch (type) {
-    case chrome::NOTIFICATION_PREF_CHANGED: {
-      const std::string& pref_name =
-          *content::Details<std::string>(details).ptr();
-      DCHECK(pref_name == prefs::kShowBookmarkBar);
-      [controller_ updateBookmarkBarVisibilityWithAnimation:YES];
-      break;
-    }
-    default:
-      NOTREACHED();  // we don't ask for anything else!
-      break;
-  }
+void BrowserWindowCocoa::OnPreferenceChanged(PrefServiceBase* service,
+                                             const std::string& pref_name) {
+  DCHECK(pref_name == prefs::kShowBookmarkBar);
+  [controller_ updateBookmarkBarVisibilityWithAnimation:YES];
 }
 
 extensions::ActiveTabPermissionGranter*
     BrowserWindowCocoa::GetActiveTabPermissionGranter() {
   TabContents* tab_contents =
       browser_->tab_strip_model()->GetActiveTabContents();
   if (!tab_contents)
     return NULL;
   extensions::TabHelper* tab_helper =
       extensions::TabHelper::FromWebContents(tab_contents->web_contents());
@@ skipping 26 matching lines @@
   AvatarMenuBubbleController* menu =
       [[AvatarMenuBubbleController alloc] initWithBrowser:browser_
                                                anchoredAt:point];
   [[menu bubble] setAlignment:info_bubble::kAlignEdgeToAnchorEdge];
   [menu showWindow:nil];
 }
 
 void BrowserWindowCocoa::ShowAvatarBubbleFromAvatarButton() {
   [[controller_ avatarButtonController] showAvatarBubble];
 }