[Sync] Inject startup dependencies into StartupController.

components/browser_sync/browser/profile_sync_service.h

 // Copyright (c) 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_BROWSER_SYNC_BROWSER_PROFILE_SYNC_SERVICE_H_
 #define COMPONENTS_BROWSER_SYNC_BROWSER_PROFILE_SYNC_SERVICE_H_
 
 #include <set>
 #include <string>
 #include <utility>
@@ skipping 736 matching lines @@
 
   // Update UMA for syncing backend.
   void UpdateBackendInitUMA(bool success);
 
   // Various setup following backend initialization, mostly for syncing backend.
   void PostBackendInitialization();
 
   // Whether sync has been authenticated with an account ID.
   bool IsSignedIn() const;
 
+  // The backend can only start if sync can start and has an auth token. This is
+  // different fron CanSyncStart because it represents whether the backend can
+  // be started at this moment, whereas CanSyncStart represents whether sync can
+  // conceptually start without further user action (acquiring a token is an
+  // automatic process).
+  bool CanBackendStart() const;
+
   // True if a syncing backend exists.
   bool HasSyncingBackend() const;
 
   // Update first sync time stored in preferences
   void UpdateFirstSyncTimePref();
 
   // Tell the sync server that this client has disabled sync.
   void RemoveClientFromServer() const;
 
   // Called when the system is under memory pressure.
@@ skipping 235 matching lines @@
   base::WeakPtrFactory<ProfileSyncService> startup_controller_weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileSyncService);
 };
 
 bool ShouldShowActionOnUI(
     const syncer::SyncProtocolError& error);
 
 
 #endif  // COMPONENTS_BROWSER_SYNC_BROWSER_PROFILE_SYNC_SERVICE_H_