Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/chromeos/drive/drive_file_system.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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_FILE_SYSTEM_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_FILE_SYSTEM_H_
 
 #include <string>
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
+#include "base/prefs/public/pref_observer.h"
 #include "base/timer.h"
 #include "chrome/browser/chromeos/drive/drive_cache.h"
 #include "chrome/browser/chromeos/drive/drive_feed_loader_observer.h"
 #include "chrome/browser/chromeos/drive/drive_file_system_interface.h"
 #include "chrome/browser/chromeos/drive/file_system/drive_operations.h"
 #include "chrome/browser/chromeos/drive/file_system/operation_observer.h"
 #include "chrome/browser/google_apis/gdata_errorcode.h"
-#include "content/public/browser/notification_observer.h"
 
 class PrefChangeRegistrar;
 
 namespace base {
 struct PlatformFileInfo;
 class SequencedTaskRunner;
 }
 
 namespace google_apis {
 class DocumentFeed;
@@ skipping 14 matching lines @@
 namespace file_system {
 class CopyOperation;
 class MoveOperation;
 class RemoveOperation;
 }
 
 // The production implementation of DriveFileSystemInterface.
 class DriveFileSystem : public DriveFileSystemInterface,
                         public DriveFeedLoaderObserver,
                         public file_system::OperationObserver,
-                        public content::NotificationObserver {
+                        public PrefObserver {
  public:
   DriveFileSystem(Profile* profile,
                   DriveCache* cache,
                   google_apis::DriveServiceInterface* drive_service,
                   google_apis::DriveUploaderInterface* uploader,
                   DriveWebAppsRegistryInterface* webapps_registry,
                   base::SequencedTaskRunner* blocking_task_runner);
   virtual ~DriveFileSystem();
 
   // DriveFileSystem overrides.
@@ skipping 69 matching lines @@
                                DriveCache::FileOperationType cache_operation,
                                const base::Closure& callback) OVERRIDE;
   virtual void UpdateEntryData(const std::string& resource_id,
                                const std::string& md5,
                                scoped_ptr<google_apis::DocumentEntry> entry,
                                const FilePath& file_content_path,
                                const base::Closure& callback) OVERRIDE;
   virtual DriveFileSystemMetadata GetMetadata() const OVERRIDE;
   virtual void Reload() OVERRIDE;
 
-  // content::NotificationObserver implementation.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
+  // PrefObserver implementation.
+  virtual void OnPreferenceChanged(PrefServiceBase* service,
+                                   const std::string& pref_name) OVERRIDE;
 
   // file_system::OperationObserver overrides.
   virtual void OnDirectoryChangedByOperation(
       const FilePath& directory_path) OVERRIDE;
 
   // DriveFeedLoader::Observer overrides.
   // Used to propagate events from DriveFeedLoader.
   virtual void OnDirectoryChanged(const FilePath& directory_path) OVERRIDE;
   virtual void OnDocumentFeedFetched(int num_accumulated_entries) OVERRIDE;
   virtual void OnFeedFromServerLoaded() OVERRIDE;
@@ skipping 604 matching lines @@
   // invalidate the weak pointers before any other members are destroyed.
   base::WeakPtrFactory<DriveFileSystem> ui_weak_ptr_factory_;
   // Unlike other classes, we need this as we need this to redirect a task
   // from IO thread to UI thread.
   base::WeakPtr<DriveFileSystem> ui_weak_ptr_;
 };
 
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_FILE_SYSTEM_H_