[Sync] Refactored ProfileSyncService and remove its backend() function

chrome/browser/sync/glue/sync_backend_host.h

 // Copyright (c) 2010 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_SYNC_GLUE_SYNC_BACKEND_HOST_H_
 #define CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_H_
 #pragma once
 
 #include <map>
 #include <string>
@@ skipping 80 matching lines @@
  private:
   DISALLOW_COPY_AND_ASSIGN(SyncFrontend);
 };
 
 // A UI-thread safe API into the sync backend that "hosts" the top-level
 // syncapi element, the SyncManager, on its own thread. This class handles
 // dispatch of potentially blocking calls to appropriate threads and ensures
 // that the SyncFrontend is only accessed on the UI loop.
 class SyncBackendHost : public browser_sync::ModelSafeWorkerRegistrar {
  public:
-  typedef sync_api::UserShare* UserShareHandle;
   typedef sync_api::SyncManager::Status::Summary StatusSummary;
   typedef sync_api::SyncManager::Status Status;
   typedef std::map<ModelSafeGroup,
                    scoped_refptr<browser_sync::ModelSafeWorker> > WorkerMap;
 
   // Create a SyncBackendHost with a reference to the |frontend| that it serves
   // and communicates to via the SyncFrontend interface (on the same thread
   // it used to call the constructor).
-  SyncBackendHost(SyncFrontend* frontend, Profile* profile);
+  explicit SyncBackendHost(Profile* profile);
   // For testing.
   // TODO(skrul): Extract an interface so this is not needed.
   SyncBackendHost();
   ~SyncBackendHost();
 
   // Called on |frontend_loop_| to kick off asynchronous initialization.
   // As a fallback when no cached auth information is available, try to
   // bootstrap authentication using |lsid|, if it isn't empty.
   // Optionally delete the Sync Data folder (if it's corrupt).
-  void Initialize(const GURL& service_url,
+  void Initialize(SyncFrontend* frontend,
+                  const GURL& service_url,
                   const syncable::ModelTypeSet& types,
                   URLRequestContextGetter* baseline_context_getter,
                   const sync_api::SyncCredentials& credentials,
                   bool delete_sync_data_folder,
                   const notifier::NotifierOptions& notifier_options);
 
   // Called from |frontend_loop| to update SyncCredentials.
   void UpdateCredentials(const sync_api::SyncCredentials& credentials);
 
   // This starts the SyncerThread running a Syncer object to communicate with
@@ skipping 55 matching lines @@
   // Requests the backend to resume.  Returns true if the request is
   // sent sucessfully.  When the backend does resume, a SYNC_RESUMED
   // notification is sent to the notification service.
   virtual bool RequestResume();
 
   // Asks the server to clear all data associated with ChromeSync.
   virtual bool RequestClearServerData();
 
   // Called on |frontend_loop_| to obtain a handle to the UserShare needed
   // for creating transactions.
-  UserShareHandle GetUserShareHandle() const;
+  sync_api::UserShare* GetUserShare() const;
 
   // Called from any thread to obtain current status information in detailed or
   // summarized form.
   Status GetDetailedStatus();
   StatusSummary GetStatusSummary();
   const GoogleServiceAuthError& GetAuthError() const;
   const sessions::SyncSessionSnapshot* GetLastSessionSnapshot() const;
 
   const FilePath& sync_data_folder_path() const {
     return sync_data_folder_path_;
@@ skipping 327 matching lines @@
 
   // Whether we've processed the initialization complete callback.
   bool syncapi_initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncBackendHost);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_H_