[Sync] Implement MemoryDumpProvider.

components/sync/engine/sync_manager.h

 // Copyright 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 COMPONENTS_SYNC_ENGINE_SYNC_MANAGER_H_
 #define COMPONENTS_SYNC_ENGINE_SYNC_MANAGER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 17 matching lines @@
 #include "components/sync/engine/net/http_post_provider_factory.h"
 #include "components/sync/engine/shutdown_reason.h"
 #include "components/sync/engine/sync_encryption_handler.h"
 #include "components/sync/engine/sync_status.h"
 #include "components/sync/protocol/sync_protocol_error.h"
 #include "components/sync/syncable/change_record.h"
 #include "google_apis/gaia/oauth2_token_service.h"
 
 class GURL;
 
+namespace base {
+namespace trace_event {
+class ProcessMemoryDump;
+}  // namespace trace_event
+}  // namespace base
+
 namespace sync_pb {
 class EncryptedData;
 }  // namespace sync_pb
 
 namespace syncer {
 
 class BaseTransaction;
 class CancelationSignal;
 class DataTypeDebugInfoListener;
 class Encryptor;
@@ skipping 340 matching lines @@
   //
   // This is an asynchronous operation that requires interaction with the sync
   // server. The operation will automatically be retried with backoff until it
   // completes successfully or sync is shutdown.
   virtual void ClearServerData(const ClearServerDataCallback& callback) = 0;
 
   // Updates Sync's tracking of whether the cookie jar has a mismatch with the
   // chrome account. See ClientConfigParams proto message for more info.
   // Note: this does not trigger a sync cycle. It just updates the sync context.
   virtual void OnCookieJarChanged(bool account_mismatch, bool empty_jar) = 0;
+
+  // Adds memory usage statistics to |pmd| for chrome://tracing.
+  virtual void OnMemoryDump(base::trace_event::ProcessMemoryDump* pmd) = 0;
 };
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_ENGINE_SYNC_MANAGER_H_