[Sync] Implement MemoryDumpProvider.

components/sync/syncable/directory.h

 // Copyright 2013 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_H_
 #define COMPONENTS_SYNC_SYNCABLE_DIRECTORY_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 12 matching lines @@
 #include "base/values.h"
 #include "components/sync/base/weak_handle.h"
 #include "components/sync/model/attachments/attachment_id.h"
 #include "components/sync/syncable/dir_open_result.h"
 #include "components/sync/syncable/entry.h"
 #include "components/sync/syncable/entry_kernel.h"
 #include "components/sync/syncable/metahandle_set.h"
 #include "components/sync/syncable/parent_child_index.h"
 #include "components/sync/syncable/syncable_delete_journal.h"
 
+namespace base {
+namespace trace_event {
+class ProcessMemoryDump;
+}
+}
+
 namespace syncer {
 
 class Cryptographer;
 class TestUserShare;
 class UnrecoverableErrorHandler;
 
 namespace syncable {
 
 class BaseTransaction;
 class BaseWriteTransaction;
@@ skipping 45 matching lines @@
     ~PersistedKernelInfo();
 
     // Set the |download_progress| entry for the given model to a
     // "first sync" start point.  When such a value is sent to the server,
     // a full download of all objects of the model will be initiated.
     void ResetDownloadProgress(ModelType model_type);
 
     // Whether a valid progress marker exists for |model_type|.
     bool HasEmptyDownloadProgress(ModelType model_type);
 
+    size_t EstimateMemoryUsage() const;
+
     // Last sync timestamp fetched from the server.
     sync_pb::DataTypeProgressMarker download_progress[MODEL_TYPE_COUNT];
     // Sync-side transaction version per data type. Monotonically incremented
     // when updating native model. A copy is also saved in native model.
     // Later out-of-sync models can be detected and fixed by comparing
     // transaction versions of sync model and native model.
     // TODO(hatiaol): implement detection and fixing of out-of-sync models.
     //                Bug 154858.
     int64_t transaction_version[MODEL_TYPE_COUNT];
     // The store birthday we were given by the server. Contents are opaque to
@@ skipping 166 matching lines @@
                            sync_pb::DataTypeProgressMarker* value_out) const;
   void GetDownloadProgressAsString(ModelType type,
                                    std::string* value_out) const;
   void SetDownloadProgress(ModelType type,
                            const sync_pb::DataTypeProgressMarker& value);
   bool HasEmptyDownloadProgress(ModelType type) const;
 
   // Gets the total number of entries in the directory.
   size_t GetEntriesCount() const;
 
+  // Adds memory statistics to |pmd| for chrome://tracing.
+  void OnMemoryDump(base::trace_event::ProcessMemoryDump* pmd);
+
   // Gets/Increments transaction version of a model type. Must be called when
   // holding kernel mutex.
   int64_t GetTransactionVersion(ModelType type) const;
   void IncrementTransactionVersion(ModelType type);
 
   // Getter/setters for the per datatype context.
   void GetDataTypeContext(BaseTransaction* trans,
                           ModelType type,
                           sync_pb::DataTypeContext* context) const;
   void SetDataTypeContext(BaseWriteTransaction* trans,
@@ skipping 358 matching lines @@
 
   base::WeakPtrFactory<Directory> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Directory);
 };
 
 }  // namespace syncable
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_SYNCABLE_DIRECTORY_H_