[Sync] Componentize synced_tab_delegate

chrome/browser/sync/sessions/sessions_sync_manager.h

Index: chrome/browser/sync/sessions/sessions_sync_manager.h
diff --git a/chrome/browser/sync/sessions/sessions_sync_manager.h b/chrome/browser/sync/sessions/sessions_sync_manager.h
index bdca8f3d4b615ded51bd4d43d9da3cbf6362640b..fe813ebd5f0b039085677188e7687035e5303176 100644
--- a/chrome/browser/sync/sessions/sessions_sync_manager.h
+++ b/chrome/browser/sync/sessions/sessions_sync_manager.h
@@ -60,7 +60,8 @@ class LocalSessionEventHandler {
  public:
   // A local navigation event took place that affects the synced session
   // for this instance of Chrome.
-  virtual void OnLocalTabModified(SyncedTabDelegate* modified_tab) = 0;
+  // Returns true if the tab had syncable data, false otherwise.
+  virtual bool OnLocalTabModified(SyncedTabDelegate* modified_tab) = 0;
 
   // A local navigation occurred that triggered updates to favicon data for
   // each page URL in |page_urls| (e.g. http://www.google.com) and the icon URL
@@ -89,6 +90,7 @@ class SessionsSyncManager : public syncer::SyncableService,
                             public LocalSessionEventHandler {
  public:
   SessionsSyncManager(
+      sync_sessions::SyncSessionsClient* sessions_client,
       Profile* profile,
       sync_driver::LocalDeviceInfoProvider* local_device,
       scoped_ptr<LocalSessionEventRouter> router,
@@ -127,7 +129,7 @@ class SessionsSyncManager : public syncer::SyncableService,
       const sync_driver::SyncedSession** local_session) override;
 
   // LocalSessionEventHandler implementation.
-  void OnLocalTabModified(SyncedTabDelegate* modified_tab) override;
+  bool OnLocalTabModified(SyncedTabDelegate* modified_tab) override;
   void OnFaviconsChanged(const std::set<GURL>& page_urls,
                          const GURL& icon_url) override;
 
@@ -343,6 +345,9 @@ class SessionsSyncManager : public syncer::SyncableService,
   // Returns false if validation fails.
   static bool IsValidSessionHeader(const sync_pb::SessionHeader& header);
 
+  // The client of this sync sessions datatype.
+  sync_sessions::SyncSessionsClient* const sessions_client_;
+
   // Mapping of current open (local) tabs to their sync identifiers.
   TabLinksMap local_tab_map_;