[Sync] Rip out overly-complicated ExtensionData class

chrome/browser/sync/glue/extension_data.h

-// Copyright (c) 2010 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_SYNC_GLUE_EXTENSION_DATA_H_
-#define CHROME_BROWSER_SYNC_GLUE_EXTENSION_DATA_H_
-#pragma once
-
-// ExtensionData is the class used to manage the client and server
-// versions of the data for a particular extension.
-
-#include <map>
-
-#include "chrome/browser/sync/protocol/extension_specifics.pb.h"
-
-namespace browser_sync {
-
-class ExtensionData {
- public:
-  enum Source {
-    CLIENT,
-    SERVER,
-  };
-
-  // Returns an ExtensionData constructed from the given data from the
-  // given source.  merged_data() will be equal to |data| and
-  // NeedsUpdate(source) will return false.
-  static ExtensionData FromData(
-      Source source, const sync_pb::ExtensionSpecifics& data);
-
-  ~ExtensionData();
-
-  // Implicit copy constructor and assignment operator welcome.
-
-  // Returns the version of the data that all sources should
-  // eventually have.
-  const sync_pb::ExtensionSpecifics& merged_data() const;
-
-  // Returns whether or not the data from the given source needs to be
-  // updated from merged_data().
-  bool NeedsUpdate(Source source) const;
-
-  // Stores the given data as being from the given source, merging it
-  // into merged_data().  May change what NeedsUpdate() returns for
-  // any source.
-  void SetData(
-      Source source, bool merge_user_properties,
-      const sync_pb::ExtensionSpecifics& data);
-
-  // Marks the data from the given data as updated,
-  // i.e. NeedsUpdate(source) will return false.
-  void ResolveData(Source source);
-
- private:
-  typedef std::map<Source, sync_pb::ExtensionSpecifics> SourceDataMap;
-  SourceDataMap source_data_;
-  sync_pb::ExtensionSpecifics merged_data_;
-
-  // This is private; clients must use FromData().
-  ExtensionData();
-};
-
-}  // namespace
-
-#endif  // CHROME_BROWSER_SYNC_GLUE_EXTENSION_DATA_H_