Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/ui/cocoa/toolbar/toolbar_controller.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.
 
 #import "chrome/browser/ui/cocoa/toolbar/toolbar_controller.h"
 
 #include <algorithm>
 
 #include "base/mac/bundle_locations.h"
 #include "base/mac/mac_util.h"
 #include "base/memory/singleton.h"
+#include "base/prefs/public/pref_observer.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/autocomplete/autocomplete_classifier.h"
 #include "chrome/browser/autocomplete/autocomplete_classifier_factory.h"
 #include "chrome/browser/autocomplete/autocomplete_match.h"
 #include "chrome/browser/command_updater.h"
 #include "chrome/browser/net/url_fixer_upper.h"
 #include "chrome/browser/prefs/pref_service.h"
@@ skipping 58 matching lines @@
 
 // The amount of left padding that the wrench menu should have.
 const CGFloat kWrenchMenuLeftPadding = 3.0;
 
 }  // namespace
 
 @interface ToolbarController()
 @property(assign, nonatomic) Browser* browser;
 - (void)addAccessibilityDescriptions;
 - (void)initCommandStatus:(CommandUpdater*)commands;
-- (void)prefChanged:(std::string*)prefName;
+- (void)prefChanged:(const std::string&)prefName;
 - (BackgroundGradientView*)backgroundGradientView;
 - (void)toolbarFrameChanged;
 - (void)pinLocationBarToLeftOfBrowserActionsContainerAndAnimate:(BOOL)animate;
 - (void)maintainMinimumLocationBarWidth;
 - (void)adjustBrowserActionsContainerForNewWindow:(NSNotification*)notification;
 - (void)browserActionsContainerDragged:(NSNotification*)notification;
 - (void)browserActionsContainerDragFinished:(NSNotification*)notification;
 - (void)browserActionsVisibilityChanged:(NSNotification*)notification;
 - (void)adjustLocationSizeBy:(CGFloat)dX animate:(BOOL)animate;
 - (void)badgeWrenchMenuIfNeeded;
 @end
 
 namespace ToolbarControllerInternal {
 
 // A class registered for C++ notifications. This is used to detect changes in
 // preferences and upgrade available notifications. Bridges the notification
 // back to the ToolbarController.
-class NotificationBridge : public content::NotificationObserver {
+class NotificationBridge
+    : public content::NotificationObserver,
+      public PrefObserver {
  public:
   explicit NotificationBridge(ToolbarController* controller)
       : controller_(controller) {
     registrar_.Add(this, chrome::NOTIFICATION_UPGRADE_RECOMMENDED,
                    content::NotificationService::AllSources());
     registrar_.Add(this, chrome::NOTIFICATION_GLOBAL_ERRORS_CHANGED,
                    content::Source<Profile>([controller browser]->profile()));
   }
 
   // Overridden from content::NotificationObserver:
   virtual void Observe(int type,
                        const content::NotificationSource& source,
-                       const content::NotificationDetails& details) {
+                       const content::NotificationDetails& details) OVERRIDE {
     switch (type) {
-      case chrome::NOTIFICATION_PREF_CHANGED:
-        [controller_ prefChanged:content::Details<std::string>(details).ptr()];
-        break;
       case chrome::NOTIFICATION_UPGRADE_RECOMMENDED:
       case chrome::NOTIFICATION_GLOBAL_ERRORS_CHANGED:
         [controller_ badgeWrenchMenuIfNeeded];
         break;
       default:
         NOTREACHED();
     }
   }
 
+  // Overridden from PrefObserver:
+  virtual void OnPreferenceChanged(PrefServiceBase* service,
+                                   const std::string& pref_name) OVERRIDE {
+    [controller_ prefChanged:pref_name];
+  }
+
  private:
   ToolbarController* controller_;  // weak, owns us
 
   content::NotificationRegistrar registrar_;
 };
 
 }  // namespace ToolbarControllerInternal
 
 @implementation ToolbarController
 
@@ skipping 411 matching lines @@
         setOverlayImageID:UpgradeDetector::GetInstance()->GetIconResourceID(
             UpgradeDetector::UPGRADE_ICON_TYPE_BADGE)];
     return;
   }
 
   int error_badge_id = GlobalErrorServiceFactory::GetForProfile(
       browser_->profile())->GetFirstBadgeResourceID();
   [[wrenchButton_ cell] setOverlayImageID:error_badge_id];
 }
 
-- (void)prefChanged:(std::string*)prefName {
-  if (!prefName) return;
-  if (*prefName == prefs::kShowHomeButton) {
+- (void)prefChanged:(const std::string&)prefName {
+  if (prefName == prefs::kShowHomeButton) {
     [self showOptionalHomeButton];
   }
 }
 
 - (void)createBrowserActionButtons {
   if (!browserActionsController_.get()) {
     browserActionsController_.reset([[BrowserActionsController alloc]
             initWithBrowser:browser_
               containerView:browserActionsContainerView_]);
     [[NSNotificationCenter defaultCenter]
@@ skipping 216 matching lines @@
 - (void)hideDropURLsIndicatorInView:(NSView*)view {
   // Do nothing.
 }
 
 // (URLDropTargetController protocol)
 - (BOOL)isUnsupportedDropData:(id<NSDraggingInfo>)info {
   return drag_util::IsUnsupportedDropData(profile_, info);
 }
 
 @end