[Sync] Remove unneeded 'using syncer::' lines and 'syncer::' scopings

sync/notifier/chrome_invalidation_client.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.
 //
 // A simple wrapper around invalidation::InvalidationClient that
 // handles all the startup/shutdown details and hookups.
 
 #ifndef SYNC_NOTIFIER_CHROME_INVALIDATION_CLIENT_H_
 #define SYNC_NOTIFIER_CHROME_INVALIDATION_CLIENT_H_
 
@@ skipping 55 matching lines @@
 
   // Calls Stop().
   virtual ~ChromeInvalidationClient();
 
   // Does not take ownership of |listener| or |state_writer|.
   // |invalidation_state_tracker| must be initialized.
   void Start(
       const std::string& client_id, const std::string& client_info,
       const std::string& state,
       const InvalidationVersionMap& initial_max_invalidation_versions,
-      const syncer::WeakHandle<InvalidationStateTracker>&
-          invalidation_state_tracker,
+      const WeakHandle<InvalidationStateTracker>& invalidation_state_tracker,
       Listener* listener);
 
   void UpdateCredentials(const std::string& email, const std::string& token);
 
   // Register the object IDs that we're interested in getting
   // notifications for.  May be called at any time.
   void RegisterIds(const ObjectIdSet& ids);
 
   // invalidation::InvalidationListener implementation.
   virtual void Ready(
@@ skipping 44 matching lines @@
   NotificationsDisabledReason GetState() const;
 
   void EmitStateChange();
 
   void EmitInvalidation(const ObjectIdPayloadMap& id_payloads);
 
   // Owned by |chrome_system_resources_|.
   notifier::PushClient* const push_client_;
   ChromeSystemResources chrome_system_resources_;
   InvalidationVersionMap max_invalidation_versions_;
-  syncer::WeakHandle<InvalidationStateTracker>
-      invalidation_state_tracker_;
+  WeakHandle<InvalidationStateTracker> invalidation_state_tracker_;
   Listener* listener_;
   scoped_ptr<invalidation::InvalidationClient> invalidation_client_;
   scoped_ptr<RegistrationManager> registration_manager_;
   // Stored to pass to |registration_manager_| on start.
   ObjectIdSet registered_ids_;
 
   // The states of the ticl and the push client (with
   // NO_NOTIFICATION_ERROR meaning notifications are enabled).
   NotificationsDisabledReason ticl_state_;
   NotificationsDisabledReason push_client_state_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeInvalidationClient);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_NOTIFIER_CHROME_INVALIDATION_CLIENT_H_