Add MDP for TabRestorer.

components/sessions/core/tab_restore_service.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_SESSIONS_CORE_TAB_RESTORE_SERVICE_H_
 #define COMPONENTS_SESSIONS_CORE_TAB_RESTORE_SERVICE_H_
 
 #include <list>
 #include <string>
 #include <vector>
@@ skipping 51 matching lines @@
     const Type type;
 
     // The time when the window or tab was closed.
     base::Time timestamp;
 
     // Is this entry from the last session? This is set to true for entries that
     // were closed during the last session, and false for entries that were
     // closed during this session.
     bool from_last_session = false;
 
+    // Estimates memory usage. By default returns 0.
+    virtual size_t EstimateMemoryUsage() const;
+
    protected:
     explicit Entry(Type type);
 
    private:
     DISALLOW_COPY_AND_ASSIGN(Entry);
   };
 
   // Represents a previously open tab.
   struct SESSIONS_EXPORT Tab : public Entry {
     Tab();
     ~Tab() override;
 
+    size_t EstimateMemoryUsage() const override;
+
     // The navigations.
     std::vector<SerializedNavigationEntry> navigations;
 
     // Index of the selected navigation in navigations.
     int current_navigation_index = -1;
 
     // The ID of the browser to which this tab belonged, so it can be restored
     // there. May be 0 (an invalid SessionID) when restoring an entire session.
     SessionID::id_type browser_id = 0;
 
@@ skipping 96 matching lines @@
 // A class that is used to associate platform-specific data with
 // TabRestoreService::Tab. See LiveTab::GetPlatformSpecificTabData().
 class SESSIONS_EXPORT PlatformSpecificTabData {
  public:
   virtual ~PlatformSpecificTabData();
 };
 
 }  // namespace sessions
 
 #endif  // COMPONENTS_SESSIONS_CORE_TAB_RESTORE_SERVICE_H_