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

chrome/browser/sync/profile_sync_service.h

Index: chrome/browser/sync/profile_sync_service.h
diff --git a/chrome/browser/sync/profile_sync_service.h b/chrome/browser/sync/profile_sync_service.h
index 88e960150b51a832890bff4c335e9bf898f17b16..c9bfd849a958ef2160cc49c1be7d777f78ae8bb7 100644
--- a/chrome/browser/sync/profile_sync_service.h
+++ b/chrome/browser/sync/profile_sync_service.h
@@ -31,6 +31,7 @@
 #include "chrome/browser/sync/glue/synced_device_tracker.h"
 #include "chrome/browser/sync/profile_sync_service_base.h"
 #include "chrome/browser/sync/profile_sync_service_observer.h"
+#include "chrome/browser/sync/sessions2/sessions_sync_manager.h"
 #include "chrome/browser/sync/sync_prefs.h"
 #include "components/browser_context_keyed_service/browser_context_keyed_service.h"
 #include "content/public/browser/notification_observer.h"
@@ -58,7 +59,9 @@ class BackendMigrator;
 class ChangeProcessor;
 class DataTypeManager;
 class DeviceInfo;
+class FaviconCache;
 class JsController;
+class OpenTabsUIDelegate;
 class SessionModelAssociator;
 
 namespace sessions {
@@ -76,6 +79,8 @@ namespace sync_pb {
 class EncryptedData;
 }  // namespace sync_pb
 
+using browser_sync::SessionsSyncManager;
+
 // ProfileSyncService is the layer between browser subsystems like bookmarks,
 // and the sync backend.  Each subsystem is logically thought of as being
 // a sync datatype.
@@ -159,16 +164,18 @@ class EncryptedData;
 //   tell the sync engine that setup is completed and it can begin downloading
 //   data from the sync server.
 //
-class ProfileSyncService : public ProfileSyncServiceBase,
-                           public browser_sync::SyncFrontend,
-                           public browser_sync::SyncPrefObserver,
-                           public browser_sync::DataTypeManagerObserver,
-                           public syncer::UnrecoverableErrorHandler,
-                           public content::NotificationObserver,
-                           public BrowserContextKeyedService,
-                           public browser_sync::DataTypeEncryptionHandler,
-                           public OAuth2TokenService::Consumer,
-                           public OAuth2TokenService::Observer {
+class ProfileSyncService
+    : public ProfileSyncServiceBase,
+      public browser_sync::SyncFrontend,
+      public browser_sync::SyncPrefObserver,
+      public browser_sync::DataTypeManagerObserver,
+      public syncer::UnrecoverableErrorHandler,
+      public content::NotificationObserver,
+      public BrowserContextKeyedService,
+      public browser_sync::DataTypeEncryptionHandler,
+      public OAuth2TokenService::Consumer,
+      public OAuth2TokenService::Observer,
+      public SessionsSyncManager::SyncInternalApiDelegate {
  public:
   typedef browser_sync::SyncBackendHost::Status Status;
 
@@ -299,13 +306,34 @@ class ProfileSyncService : public ProfileSyncServiceBase,
   // Returns the session model associator associated with this type, but only if
   // the associator is running.  If it is doing anything else, it will return
   // null.
-  // TODO(zea): Figure out a better way to expose this to the UI elements that
-  // need it.
-  virtual browser_sync::SessionModelAssociator* GetSessionModelAssociator();
+  //
+  // *** DONT USE THIS ANYMORE! ***
+  // If you think you want to use this, think again! Can you use
+  // GetOpenTabsUIDelegate instead?
+  // TODO(tim): Remove this method.
+  virtual browser_sync::SessionModelAssociator*
+      GetSessionModelAssociatorDeprecated();
+
+  // Return the active OpenTabsUIDelegate. If sessions is not enabled or not
+  // currently syncing, returns NULL.
+  virtual browser_sync::OpenTabsUIDelegate* GetOpenTabsUIDelegate();
 
+  // Returns the SyncableService for syncer::SESSIONS.
+  virtual syncer::SyncableService* GetSessionsSyncableService();
+
+  // SyncInternalApiDelegate implementation.
+  //
   // Returns sync's representation of the local device info.
   // Return value is an empty scoped_ptr if the device info is unavailable.
-  virtual scoped_ptr<browser_sync::DeviceInfo> GetLocalDeviceInfo() const;
+  virtual scoped_ptr<browser_sync::DeviceInfo> GetLocalDeviceInfo()
+      const OVERRIDE;
+
+  // Gets the guid for the local device. Can be used by other layers to
+  // to distinguish sync data that belongs to the local device vs data
+  // that belongs to remote devices. Returns empty string if sync is not
+  // initialized. The GUID is not persistent across Chrome signout/signin.
+  // If you sign out of Chrome and sign in, a new GUID is generated.
+  virtual std::string GetLocalSyncCacheGUID() const OVERRIDE;
 
   // Returns sync's representation of the device info for a client identified
   // by |client_id|. Return value is an empty scoped ptr if the device info
@@ -317,12 +345,6 @@ class ProfileSyncService : public ProfileSyncServiceBase,
   // with this profile.
   virtual ScopedVector<browser_sync::DeviceInfo> GetAllSignedInDevices() const;
 
-  // Gets the partnership guid for the local device. Can be used by other
-  // layers to distinguish sync data that belongs to the local device vs
-  // data that belong to remote devices. Returns null if sync is not
-  // initialized.
-  virtual std::string GetLocalDeviceGUID() const;
-
   // Notifies the observer of any device info changes.
   virtual void AddObserverForDeviceInfoChange(
       browser_sync::SyncedDeviceTracker::Observer* observer);
@@ -675,6 +697,8 @@ class ProfileSyncService : public ProfileSyncServiceBase,
   // Return sync token status.
   SyncTokenStatus GetSyncTokenStatus() const;
 
+  browser_sync::FaviconCache* GetFaviconCache();
+
  protected:
   // Used by test classes that derive from ProfileSyncService.
   virtual browser_sync::SyncBackendHost* GetBackendForTest();
@@ -1014,6 +1038,8 @@ class ProfileSyncService : public ProfileSyncServiceBase,
   GoogleServiceAuthError last_get_token_error_;
   base::Time next_token_request_time_;
 
+  scoped_ptr<SessionsSyncManager> sessions_sync_manager_;
+
   DISALLOW_COPY_AND_ASSIGN(ProfileSyncService);
 };