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

chrome/browser/sync/glue/sync_backend_host.cc

 // 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.
 
 #include "build/build_config.h"
 
 #include <algorithm>
 
 #include "base/compiler_specific.h"
 #include "base/command_line.h"
@@ skipping 33 matching lines @@
 using browser_sync::DataTypeController;
 typedef TokenService::TokenAvailableDetails TokenAvailableDetails;
 
 typedef GoogleServiceAuthError AuthError;
 
 namespace browser_sync {
 
 using sessions::SyncSessionSnapshot;
 using sync_api::SyncCredentials;
 
-SyncBackendHost::SyncBackendHost(SyncFrontend* frontend, Profile* profile)
+SyncBackendHost::SyncBackendHost(Profile* profile)
     : core_(new Core(ALLOW_THIS_IN_INITIALIZER_LIST(this))),
       core_thread_("Chrome_SyncCoreThread"),
       frontend_loop_(MessageLoop::current()),
       profile_(profile),
-      frontend_(frontend),
+      frontend_(NULL),
       sync_data_folder_path_(
           profile_->GetPath().Append(kSyncDataFolderName)),
       last_auth_error_(AuthError::None()),
       syncapi_initialized_(false) {
 }
 
 SyncBackendHost::SyncBackendHost()
     : core_thread_("Chrome_SyncCoreThread"),
       frontend_loop_(MessageLoop::current()),
       profile_(NULL),
       frontend_(NULL),
       last_auth_error_(AuthError::None()),
       syncapi_initialized_(false) {
 }
 
 SyncBackendHost::~SyncBackendHost() {
   DCHECK(!core_ && !frontend_) << "Must call Shutdown before destructor.";
   DCHECK(registrar_.workers.empty());
 }
 
 void SyncBackendHost::Initialize(
+    SyncFrontend* frontend,
     const GURL& sync_service_url,
     const syncable::ModelTypeSet& types,
     URLRequestContextGetter* baseline_context_getter,
     const SyncCredentials& credentials,
     bool delete_sync_data_folder,
     const notifier::NotifierOptions& notifier_options) {
   if (!core_thread_.Start())
     return;
 
+  frontend_ = frontend;
+  DCHECK(frontend);
+
   // Create a worker for the UI thread and route bookmark changes to it.
   // TODO(tim): Pull this into a method to reuse.  For now we don't even
   // need to lock because we init before the syncapi exists and we tear down
   // after the syncapi is destroyed.  Make sure to NULL-check workers_ indices
   // when a new type is synced as the worker may already exist and you just
   // need to update routing_info_.
   registrar_.workers[GROUP_DB] = new DatabaseModelWorker();
   registrar_.workers[GROUP_UI] = new UIModelWorker(frontend_loop_);
   registrar_.workers[GROUP_PASSIVE] = new ModelSafeWorker();
 
@@ skipping 793 matching lines @@
 }
 
 void SyncBackendHost::Core::DeleteSyncDataFolder() {
   if (file_util::DirectoryExists(host_->sync_data_folder_path())) {
     if (!file_util::Delete(host_->sync_data_folder_path(), true))
       LOG(DFATAL) << "Could not delete the Sync Data folder.";
   }
 }
 
 }  // namespace browser_sync