[WIP][tracing] Add memory dump provider for sync Directory

sync/internal_api/public/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 SYNC_INTERNAL_API_PUBLIC_SYNC_MANAGER_H_
 #define SYNC_INTERNAL_API_PUBLIC_SYNC_MANAGER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 19 matching lines @@
 #include "sync/internal_api/public/http_post_provider_factory.h"
 #include "sync/internal_api/public/internal_components_factory.h"
 #include "sync/internal_api/public/model_type_connector.h"
 #include "sync/internal_api/public/shutdown_reason.h"
 #include "sync/internal_api/public/sync_encryption_handler.h"
 #include "sync/internal_api/public/util/weak_handle.h"
 #include "sync/protocol/sync_protocol_error.h"
 
 class GURL;
 
+namespace base {
+namespace trace_event {
+class ProcessMemoryDump;
+}
+}
+
 namespace sync_pb {
 class EncryptedData;
 }  // namespace sync_pb
 
 namespace syncer {
 
 class BaseTransaction;
 class CancelationSignal;
 class DataTypeDebugInfoListener;
 class Encryptor;
@@ skipping 287 matching lines @@
   virtual void AddObserver(Observer* observer) = 0;
 
   // Remove the given observer.  Make sure to call this if the
   // Observer is being destroyed so the SyncManager doesn't
   // potentially dereference garbage.
   virtual void RemoveObserver(Observer* observer) = 0;
 
   // Status-related getter.  May be called on any thread.
   virtual SyncStatus GetDetailedStatus() const = 0;
 
+  // Adds memory usage statistics to |pmd| for chrome://tracing.
+  virtual void OnMemoryDump(base::trace_event::ProcessMemoryDump* pmd) = 0;
+
   // Call periodically from a database-safe thread to persist recent changes
   // to the syncapi model.
   virtual void SaveChanges() = 0;
 
   // Issue a final SaveChanges, and close sqlite handles.
   virtual void ShutdownOnSyncThread(ShutdownReason reason) = 0;
 
   // May be called from any thread.
   virtual UserShare* GetUserShare() = 0;
 
@@ skipping 47 matching lines @@
 
   // 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;
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_SYNC_MANAGER_H_