Add MDP for TabRestorer.

components/sessions/core/tab_restore_service_helper.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_HELPER_H_
 #define COMPONENTS_SESSIONS_CORE_TAB_RESTORE_SERVICE_HELPER_H_
 
 #include <set>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "base/time/time.h"
+#include "base/trace_event/memory_dump_provider.h"
 #include "components/sessions/core/session_id.h"
 #include "components/sessions/core/session_types.h"
 #include "components/sessions/core/sessions_export.h"
 #include "components/sessions/core/tab_restore_service.h"
 
 namespace sessions {
 
 class TabRestoreService;
 class TabRestoreServiceClient;
 class LiveTabContext;
 class TabRestoreServiceObserver;
 class TimeFactory;
 
 // Helper class used to implement InMemoryTabRestoreService and
 // PersistentTabRestoreService. See tab_restore_service.h for method-level
 // comments.
-class SESSIONS_EXPORT TabRestoreServiceHelper {
+class SESSIONS_EXPORT TabRestoreServiceHelper
+    : public base::trace_event::MemoryDumpProvider {
  public:
   typedef TabRestoreService::Entries Entries;
   typedef TabRestoreService::Entry Entry;
   typedef TabRestoreService::Tab Tab;
   typedef TabRestoreService::TimeFactory TimeFactory;
   typedef TabRestoreService::Window Window;
 
   // Provides a way for the client to add behavior to the tab restore service
   // helper (e.g. implementing tabs persistence).
   class Observer {
@@ skipping 19 matching lines @@
   };
 
   // Creates a new TabRestoreServiceHelper and provides an object that provides
   // the current time. The TabRestoreServiceHelper does not take ownership of
   // |time_factory| and |observer|. Note that |observer| can also be NULL.
   TabRestoreServiceHelper(TabRestoreService* tab_restore_service,
                           Observer* observer,
                           TabRestoreServiceClient* client,
                           TimeFactory* time_factory);
 
-  ~TabRestoreServiceHelper();
+  ~TabRestoreServiceHelper() override;
 
   // Helper methods used to implement TabRestoreService.
   void AddObserver(TabRestoreServiceObserver* observer);
   void RemoveObserver(TabRestoreServiceObserver* observer);
   void CreateHistoricalTab(LiveTab* live_tab, int index);
   void BrowserClosing(LiveTabContext* context);
   void BrowserClosed(LiveTabContext* context);
   void ClearEntries();
   const Entries& entries() const;
   std::vector<LiveTab*> RestoreMostRecentEntry(LiveTabContext* context);
@@ skipping 18 matching lines @@
   // Prunes |entries_| to contain only kMaxEntries, and removes uninteresting
   // entries.
   void PruneEntries();
 
   // Returns an iterator into |entries_| whose id matches |id|. If |id|
   // identifies a Window, then its iterator position will be returned. If it
   // identifies a tab, then the iterator position of the Window in which the Tab
   // resides is returned.
   Entries::iterator GetEntryIteratorById(SessionID::id_type id);
 
+  // From base::trace_event::MemoryDumpProvider
+  bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
+                    base::trace_event::ProcessMemoryDump* pmd) override;
+
   // Calls either ValidateTab or ValidateWindow as appropriate.
   static bool ValidateEntry(const Entry& entry);
 
  private:
   friend class PersistentTabRestoreService;
 
   // Populates the tab's navigations from the LiveTab, and its browser_id and
   // pinned state from the context.
   void PopulateTab(Tab* tab,
                    int index,
@@ skipping 57 matching lines @@
   std::set<LiveTabContext*> closing_contexts_;
 
   TimeFactory* const time_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TabRestoreServiceHelper);
 };
 
 }  // namespace sessions
 
 #endif  // COMPONENTS_SESSIONS_CORE_TAB_RESTORE_SERVICE_HELPER_H_