Add MDP for TabRestorer.

components/sessions/core/tab_restore_service.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 "components/sessions/core/tab_restore_service.h"
 
+#include "base/trace_event/estimate_memory_usage.h"
+
 namespace sessions {
 
 // TimeFactory-----------------------------------------------------------------
 
 TabRestoreService::TimeFactory::~TimeFactory() {}
 
 // Entry ----------------------------------------------------------------------
 
 // ID of the next Entry.
 static SessionID::id_type next_entry_id = 1;
 
 TabRestoreService::Entry::~Entry() = default;
 TabRestoreService::Entry::Entry(Type type) : id(next_entry_id++), type(type) {}
 
+size_t TabRestoreService::Entry::EstimateMemoryUsage() const {
+  return 0;
+}
+
 TabRestoreService::Tab::Tab() : Entry(TAB) {}
 TabRestoreService::Tab::~Tab() = default;
 
+size_t TabRestoreService::Tab::EstimateMemoryUsage() const {
+  using base::trace_event::EstimateMemoryUsage;
+  return
+      EstimateMemoryUsage(navigations) +
+      EstimateMemoryUsage(extension_app_id) +
+      EstimateMemoryUsage(user_agent_override);
+}
+
 TabRestoreService::Window::Window() : Entry(WINDOW) {}
 TabRestoreService::Window::~Window() = default;
 
 // TabRestoreService ----------------------------------------------------------
 
 TabRestoreService::~TabRestoreService() {
 }
 
 // PlatformSpecificTabData
 // ------------------------------------------------------
 
 PlatformSpecificTabData::~PlatformSpecificTabData() {}
 
 }  // namespace sessions