content: convert zoom notifications to observer usage

chrome/browser/profiles/profile_impl.h

 // 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.
 
 // This class gathers state related to a single user profile.
 
 #ifndef CHROME_BROWSER_PROFILES_PROFILE_IMPL_H_
 #define CHROME_BROWSER_PROFILES_PROFILE_IMPL_H_
 
 #include <string>
@@ skipping 112 matching lines @@
 #if defined(OS_CHROMEOS)
   virtual void ChangeAppLocale(const std::string& locale,
                                AppLocaleChangedVia) OVERRIDE;
   virtual void OnLogin() OVERRIDE;
   virtual void SetupChromeOSEnterpriseExtensionObserver() OVERRIDE;
   virtual void InitChromeOSPreferences() OVERRIDE;
 #endif  // defined(OS_CHROMEOS)
 
   virtual PrefProxyConfigTracker* GetProxyConfigTracker() OVERRIDE;
 
+  void OnZoomLevelChanged(const std::string& host);

[jam, 2013/01/30 17:50:44]

nit: private if you can. also in other files

+
   // content::NotificationObserver implementation.
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
  private:
   friend class Profile;
   friend class BetterSessionRestoreCrashTest;
   FRIEND_TEST_ALL_PREFIXES(StartupBrowserCreatorTest,
                            ProfilesLaunchedAfterCrash);
@@ skipping 127 matching lines @@
   //   chrome/browser/profile/profile_keyed_dependency_manager.{h,cc}
 
   Profile::Delegate* delegate_;
 
   chrome_browser_net::Predictor* predictor_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileImpl);
 };
 
 #endif  // CHROME_BROWSER_PROFILES_PROFILE_IMPL_H_