[Sync] Implement MemoryDumpProvider.

components/sync/syncable/directory_backing_store.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_SYNCABLE_DIRECTORY_BACKING_STORE_H_
 #define COMPONENTS_SYNC_SYNCABLE_DIRECTORY_BACKING_STORE_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/threading/non_thread_safe.h"
 #include "components/sync/base/model_type.h"
 #include "components/sync/syncable/dir_open_result.h"
 #include "components/sync/syncable/directory.h"
 #include "components/sync/syncable/metahandle_set.h"
 #include "sql/connection.h"
 #include "sql/statement.h"
 
+namespace base {
+namespace trace_event {
+class MemoryAllocatorDump;
+}
+}
+
 namespace sync_pb {
 class EntitySpecifics;
 }
 
 namespace syncer {
 namespace syncable {
 
 extern const int32_t kCurrentDBVersion;
 extern const int32_t kCurrentPageSizeKB;
 
@@ skipping 60 matching lines @@
   //
   // There can be at most one handler. If this method is invoked when there is
   // already a handler, the existing handler is overwritten with
   // |catastrophic_error_handler|.
   virtual void SetCatastrophicErrorHandler(
       const base::Closure& catastrophic_error_handler);
 
   // Returns true on success, false on error.
   bool GetDatabasePageSize(int* page_size);
 
+  bool ReportMemoryUsage(base::trace_event::MemoryAllocatorDump* mad);
+
  protected:
   // For test classes.
   DirectoryBackingStore(const std::string& dir_name,
                         sql::Connection* connection);
 
   // An accessor for the underlying sql::Connection. Avoid using outside of
   // tests.
   sql::Connection* db();
 
   // Return true if the DB is open.
@@ skipping 148 matching lines @@
   // sql::Connection is destroyed/recreated.
   base::Closure catastrophic_error_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(DirectoryBackingStore);
 };
 
 }  // namespace syncable
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_SYNCABLE_DIRECTORY_BACKING_STORE_H_