[Sync] Rip out overly-complicated ExtensionData class

chrome/browser/sync/glue/extension_data.cc

-// 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.
-
-#include "chrome/browser/sync/glue/extension_data.h"
-
-#include "base/logging.h"
-#include "chrome/browser/sync/glue/extension_util.h"
-
-namespace browser_sync {
-
-ExtensionData ExtensionData::FromData(
-    Source source, const sync_pb::ExtensionSpecifics& data) {
-  DcheckIsExtensionSpecificsValid(data);
-  ExtensionData extension_data;
-  extension_data.merged_data_ = extension_data.source_data_[source] = data;
-  DCHECK(AreExtensionSpecificsEqual(extension_data.merged_data(), data));
-  DCHECK(!extension_data.NeedsUpdate(source));
-  return extension_data;
-}
-
-ExtensionData::~ExtensionData() {}
-
-const sync_pb::ExtensionSpecifics& ExtensionData::merged_data() const {
-  DcheckIsExtensionSpecificsValid(merged_data_);
-  return merged_data_;
-}
-
-bool ExtensionData::NeedsUpdate(Source source) const {
-  SourceDataMap::const_iterator it = source_data_.find(source);
-  return
-      (it == source_data_.end()) ||
-      !AreExtensionSpecificsEqual(it->second, merged_data_);
-}
-
-void ExtensionData::SetData(
-    Source source, bool merge_user_properties,
-    const sync_pb::ExtensionSpecifics& data) {
-  DcheckIsExtensionSpecificsValid(data);
-  source_data_[source] = data;
-  MergeExtensionSpecifics(data, merge_user_properties, &merged_data_);
-  DcheckIsExtensionSpecificsValid(merged_data_);
-}
-
-void ExtensionData::ResolveData(Source source) {
-  source_data_[source] = merged_data_;
-  DCHECK(!NeedsUpdate(source));
-}
-
-ExtensionData::ExtensionData() {}
-
-}  // namespace browser_sync