Cleanup: IWYU for base/time.h in sync/.

sync/internal_api/public/base_node.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 SYNC_INTERNAL_API_PUBLIC_BASE_NODE_H_
 #define SYNC_INTERNAL_API_PUBLIC_BASE_NODE_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/time.h"
 #include "googleurl/src/gurl.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/protocol/sync.pb.h"
 
 // Forward declarations of internal class types so that sync API objects
 // may have opaque pointers to these types.
 namespace base {
 class DictionaryValue;
 }
 
@@ skipping 57 matching lines @@
       ModelType model_type,
       const std::string& tag) = 0;
 
   // Each object is identified by a 64-bit id (internally, the syncable
   // metahandle).  These ids are strictly local handles.  They will persist
   // on this client, but the same object on a different client may have a
   // different ID value.
   virtual int64 GetId() const;
 
   // Returns the modification time of the object.
-  const base::Time& GetModificationTime() const;
+  base::Time GetModificationTime() const;
 
   // Nodes are hierarchically arranged into a single-rooted tree.
   // InitByRootLookup on ReadNode allows access to the root. GetParentId is
   // how you find a node's parent.
   int64 GetParentId() const;
 
   // Nodes are either folders or not.  This corresponds to the IS_DIR property
   // of syncable::Entry.
   bool GetIsFolder() const;
 
@@ skipping 144 matching lines @@
 
   // Same as |unencrypted_data_|, but for legacy password encryption.
   scoped_ptr<sync_pb::PasswordSpecificsData> password_data_;
 
   DISALLOW_COPY_AND_ASSIGN(BaseNode);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_BASE_NODE_H_