sync: Add --enable-sync-sessions-v2 and necessary plumbing to use SessionsSyncManager.

chrome/browser/ui/toolbar/recent_tabs_sub_menu_model.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 CHROME_BROWSER_UI_TOOLBAR_RECENT_TABS_SUB_MENU_MODEL_H_
 #define CHROME_BROWSER_UI_TOOLBAR_RECENT_TABS_SUB_MENU_MODEL_H_
 
 #include <set>
 
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/favicon/favicon_service.h"
 #include "chrome/browser/sessions/tab_restore_service.h"
 #include "chrome/browser/sessions/tab_restore_service_observer.h"
 #include "chrome/browser/sync/glue/synced_session.h"
 #include "chrome/common/cancelable_task_tracker.h"
 #include "ui/base/accelerators/accelerator.h"
 #include "ui/base/models/simple_menu_model.h"
 
 class Browser;
 struct SessionTab;
 
 namespace browser_sync {
-class SessionModelAssociator;
+class OpenTabsUIDelegate;
 }
 
 namespace chrome {
 struct FaviconImageResult;
 }
 
 namespace gfx {
 class Image;
 }
 
 namespace ui {
 class AcceleratorProvider;
 }
 
 // A menu model that builds the contents of "Recent tabs" submenu, which include
 // the recently closed tabs/windows of current device i.e. local entries, and
 // opened tabs of other devices.
 class RecentTabsSubMenuModel : public ui::SimpleMenuModel,
                                public ui::SimpleMenuModel::Delegate,
                                public TabRestoreServiceObserver {
  public:
   // Command Id for recently closed items header or disabled item to which the
   // accelerator string will be appended.
   static const int kRecentlyClosedHeaderCommandId;
   static const int kDisabledRecentlyClosedHeaderCommandId;
 
-  // If |associator| is NULL, default associator for |browser|'s profile will
-  // be used.  Testing may require a specific |associator|.
+  // If |open_tabs_delegate| is NULL, the default delegate for |browser|'s
+  // profile will be used. Testing may require a specific |open_tabs_delegate|.
   RecentTabsSubMenuModel(ui::AcceleratorProvider* accelerator_provider,
                          Browser* browser,
-                         browser_sync::SessionModelAssociator* associator);
+                         browser_sync::OpenTabsUIDelegate* open_tabs_delegate);
   virtual ~RecentTabsSubMenuModel();
 
   // Overridden from ui::SimpleMenuModel::Delegate:
   virtual bool IsCommandIdChecked(int command_id) const OVERRIDE;
   virtual bool IsCommandIdEnabled(int command_id) const OVERRIDE;
   virtual bool GetAcceleratorForCommandId(
       int command_id,
       ui::Accelerator* accelerator) OVERRIDE;
   virtual void ExecuteCommand(int command_id, int event_flags) OVERRIDE;
   virtual const gfx::Font* GetLabelFontAt(int index) const OVERRIDE;
@@ skipping 45 matching lines @@
   void OnFaviconDataAvailable(int command_id,
                               const chrome::FaviconImageResult& image_result);
 
   // Clear all recently closed tabs and windows.
   void ClearLocalEntries();
 
   // Converts |command_id| of menu item to index in local or other devices'
   // TabNavigationItems, and returns the corresponding local or other devices'
   // TabNavigationItems in |tab_items|.
   int CommandIdToTabVectorIndex(int command_id, TabNavigationItems** tab_items);
-  browser_sync::SessionModelAssociator* GetModelAssociator();
+
+  // Used to access (and lazily initialize) open_tabs_delegate_.
+  // TODO(tim): This lazy-init for member variables is error prone because you
+  // can always skip going through the function and access the field directly.
+  // Consider instead having code just deal with potentially NULL open_tabs_
+  // and have it initialized by an event / callback.
+  browser_sync::OpenTabsUIDelegate* GetOpenTabsUIDelegate();
 
   // Overridden from TabRestoreServiceObserver:
   virtual void TabRestoreServiceChanged(TabRestoreService* service) OVERRIDE;
   virtual void TabRestoreServiceDestroyed(TabRestoreService* service) OVERRIDE;
 
   Browser* browser_;  // Weak.
 
-  browser_sync::SessionModelAssociator* associator_;  // Weak.
+  browser_sync::OpenTabsUIDelegate* open_tabs_delegate_;  // Weak.
 
   // Accelerator for reopening last closed tab.
   ui::Accelerator reopen_closed_tab_accelerator_;
 
   // Navigation items for local recently closed tabs.  The |command_id| for
   // these is set to |kFirstLocalTabCommandId| plus the index into the vector.
   // Upon invocation of the menu, the navigation information is retrieved from
   // |local_tab_navigation_items_| and used to navigate to the item specified.
   TabNavigationItems local_tab_navigation_items_;
 
@@ skipping 16 matching lines @@
 
   CancelableTaskTracker local_tab_cancelable_task_tracker_;
   CancelableTaskTracker other_devices_tab_cancelable_task_tracker_;
 
   base::WeakPtrFactory<RecentTabsSubMenuModel> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RecentTabsSubMenuModel);
 };
 
 #endif  // CHROME_BROWSER_UI_TOOLBAR_RECENT_TABS_SUB_MENU_MODEL_H_