Add non-blocking sync code to ProfileSyncService

chrome/browser/sync/glue/sync_backend_host_core.cc

 // Copyright 2013 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 "chrome/browser/sync/glue/sync_backend_host_core.h"
 
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/metrics/histogram.h"
 #include "chrome/browser/sync/glue/device_info.h"
@@ skipping 456 matching lines @@
   // provide a callback for when it finishes.
   synced_device_tracker_.reset(
       new SyncedDeviceTracker(sync_manager_->GetUserShare(),
                               sync_manager_->cache_guid()));
   synced_device_tracker_->InitLocalDeviceInfo(
       base::Bind(&SyncBackendHostCore::DoFinishInitialProcessControlTypes,
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
 void SyncBackendHostCore::DoFinishInitialProcessControlTypes() {
+  DCHECK_EQ(base::MessageLoop::current(), sync_loop_);
+
   registrar_->ActivateDataType(syncer::DEVICE_INFO,
                                syncer::GROUP_PASSIVE,
                                synced_device_tracker_.get(),
                                sync_manager_->GetUserShare());
 
+  base::WeakPtr<syncer::SyncCore> sync_core = sync_manager_->GetSyncCore();
+
+  // De-reference the WeakPtr while we're here to signal to the debugging
+  // mechanisms that it belongs to the sync thread.  This helps us DCHECK
+  // earlier if the pointer is misused.
+  sync_core.get();
+
   host_.Call(
       FROM_HERE,
       &SyncBackendHostImpl::HandleInitializationSuccessOnFrontendLoop,
       js_backend_,
-      debug_info_listener_);
+      debug_info_listener_,
+      syncer::SyncCoreProxy(base::MessageLoopProxy::current(), sync_core));
 
   js_backend_.Reset();
   debug_info_listener_.Reset();
 }
 
 void SyncBackendHostCore::DoSetDecryptionPassphrase(
     const std::string& passphrase) {
   DCHECK_EQ(base::MessageLoop::current(), sync_loop_);
   sync_manager_->GetEncryptionHandler()->SetDecryptionPassphrase(
       passphrase);
@@ skipping 155 matching lines @@
       this, &SyncBackendHostCore::SaveChanges);
 }
 
 void SyncBackendHostCore::SaveChanges() {
   DCHECK_EQ(base::MessageLoop::current(), sync_loop_);
   sync_manager_->SaveChanges();
 }
 
 }  // namespace browser_sync