[Sync] Implement EstimateMemoryUsage for SharedModelTypeProcessor and ModelTypeWorker

components/sync/model_impl/processor_entity_tracker.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_MODEL_IMPL_PROCESSOR_ENTITY_TRACKER_H_
 #define COMPONENTS_SYNC_MODEL_IMPL_PROCESSOR_ENTITY_TRACKER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 104 matching lines @@
   bool MatchesData(const EntityData& data) const;
 
   // Check whether |data| matches the stored base (shared between client and
   // server) specifics hash.
   bool MatchesBaseData(const EntityData& data) const;
 
   // Increment sequence number in the metadata. This will also update the
   // base_specifics_hash if the entity was not already unsynced.
   void IncrementSequenceNumber();
 
+  // Returns the estimate of dynamically allocated memory in bytes.
+  size_t EstimateMemoryUsage() const;
+
  private:
   friend class ProcessorEntityTrackerTest;
 
   // The constructor swaps the data from the passed metadata.
   ProcessorEntityTracker(const std::string& storage_key,
                          sync_pb::EntityMetadata* metadata);
 
   // Check whether |specifics| matches the stored specifics_hash.
   bool MatchesSpecificsHash(const sync_pb::EntitySpecifics& specifics) const;
 
@@ skipping 10 matching lines @@
   // The data is reset once commit confirmation is received.
   EntityDataPtr commit_data_;
 
   // The sequence number of the last item sent to the sync thread.
   int64_t commit_requested_sequence_number_;
 };
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_MODEL_IMPL_PROCESSOR_ENTITY_TRACKER_H_