Reland: [Sync] Record sync memory usage in histogram broken by datatypes

components/sync/driver/proxy_data_type_controller.cc

 // 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.
 
 #include "components/sync/driver/proxy_data_type_controller.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/values.h"
 #include "components/sync/engine/model_safe_worker.h"
 #include "components/sync/engine/model_type_configurer.h"
@@ skipping 67 matching lines @@
 void ProxyDataTypeController::GetAllNodes(const AllNodesCallback& callback) {
   callback.Run(type(), base::MakeUnique<base::ListValue>());
 }
 
 void ProxyDataTypeController::GetStatusCounters(
     const StatusCountersCallback& callback) {
   syncer::StatusCounters counters;
   callback.Run(type(), counters);
 }
 
+void ProxyDataTypeController::RecordMemoryUsageHistogram() {}
+
 }  // namespace syncer