[Sync] Move //components/sync to the syncer namespace.

components/sync/driver/sync_type_preference_provider.h

 // Copyright 2014 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 COMPONENTS_SYNC_DRIVER_SYNC_TYPE_PREFERENCE_PROVIDER_H_
 #define COMPONENTS_SYNC_DRIVER_SYNC_TYPE_PREFERENCE_PROVIDER_H_
 
 #include "components/sync/base/model_type.h"
 
+namespace syncer {
+
 class SyncTypePreferenceProvider {
  public:
-  virtual syncer::ModelTypeSet GetPreferredDataTypes() const = 0;
+  virtual ModelTypeSet GetPreferredDataTypes() const = 0;
 
  protected:
   virtual ~SyncTypePreferenceProvider() {}
 };
 
+}  // namespace syncer
+
 #endif  // COMPONENTS_SYNC_DRIVER_SYNC_TYPE_PREFERENCE_PROVIDER_H_