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

sync/syncable/entry_kernel.cc

 // Copyright (c) 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.
 
 #include "sync/syncable/entry_kernel.h"
 
 #include <stdint.h>
 #include <utility>
 
 #include "base/json/string_escape.h"
 #include "base/strings/string_number_conversions.h"
 #include "sync/protocol/proto_value_conversions.h"
 #include "sync/syncable/syncable_columns.h"
 #include "sync/syncable/syncable_enum_conversions.h"
 #include "sync/util/cryptographer.h"
 
 namespace syncer {
 namespace syncable {
 
-EntryKernel::EntryKernel() : dirty_(false) {
+EntryKernel::EntryKernel() : dirty_(false), cached_size_(0) {
   // Everything else should already be default-initialized.
   for (int i = 0; i < INT64_FIELDS_COUNT; ++i) {
     int64_fields[i] = 0;
   }
 }
 
 EntryKernel::EntryKernel(const EntryKernel& other) = default;
 
 EntryKernel::~EntryKernel() {}
 
@@ skipping 256 matching lines @@
   os << "TempFlags: ";
   for (; i < BIT_TEMPS_END; ++i) {
     if (kernel->ref(static_cast<BitTemp>(i)))
       os << "#" << i - BIT_TEMPS_BEGIN << ", ";
   }
   return os;
 }
 
 }  // namespace syncable
 }  // namespace syncer