DriveFileSyncService listens to OnAuthenticated event to recover from unavailable state

chrome/browser/sync_file_system/drive_file_sync_service.cc

 // 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.
 
 #include "chrome/browser/sync_file_system/drive_file_sync_service.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 121 matching lines @@
 }
 
 DriveFileSyncService::DriveFileSyncService(Profile* profile)
     : last_operation_status_(fileapi::SYNC_STATUS_OK),
       state_(REMOTE_SERVICE_OK),
       largest_changestamp_(0),
       weak_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
   token_.reset(new TaskToken(AsWeakPtr()));
 
   sync_client_.reset(new DriveFileSyncClient(profile));
+  sync_client_->AddObserver(this);
 
   metadata_store_.reset(new DriveMetadataStore(
       profile->GetPath(),
       content::BrowserThread::GetMessageLoopProxyForThread(
           content::BrowserThread::FILE)));
 
   metadata_store_->Initialize(
       base::Bind(&DriveFileSyncService::DidInitializeMetadataStore, AsWeakPtr(),
                  base::Passed(GetToken(FROM_HERE, TASK_TYPE_DATABASE,
                                        "Metadata database initialization"))));
 }
 
 DriveFileSyncService::~DriveFileSyncService() {
   // Invalidate WeakPtr instances here explicitly to notify TaskToken that we
   // can safely discard the token.
   weak_factory_.InvalidateWeakPtrs();
+  sync_client_->RemoveObserver(this);
   token_.reset();
 }
 
 // static
 scoped_ptr<DriveFileSyncService> DriveFileSyncService::CreateForTesting(
     scoped_ptr<DriveFileSyncClient> sync_client,
     scoped_ptr<DriveMetadataStore> metadata_store) {
   return make_scoped_ptr(new DriveFileSyncService(
       sync_client.Pass(), metadata_store.Pass()));
 }
@@ skipping 197 matching lines @@
       DidApplyLocalChange(token.Pass(), url, google_apis::GDATA_OTHER_ERROR,
                           callback, fileapi::SYNC_STATUS_FAILED);
       return;
     }
   }
   NOTREACHED();
   DidApplyLocalChange(token.Pass(), url, google_apis::GDATA_OTHER_ERROR,
                       callback, fileapi::SYNC_STATUS_FAILED);
 }
 
+void DriveFileSyncService::OnAuthenticated() {
+  FOR_EACH_OBSERVER(
+        Observer, observers_,
+        OnRemoteServiceStateUpdated(REMOTE_SERVICE_OK, "Authenticated"));
+}
+
 // Called by CreateForTesting.
 DriveFileSyncService::DriveFileSyncService(
     scoped_ptr<DriveFileSyncClient> sync_client,
     scoped_ptr<DriveMetadataStore> metadata_store)
     : last_operation_status_(fileapi::SYNC_STATUS_OK),
       state_(REMOTE_SERVICE_OK),
       largest_changestamp_(0),
       weak_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
   token_.reset(new TaskToken(AsWeakPtr()));
   sync_client_ = sync_client.Pass();
@@ skipping 482 matching lines @@
   if (found_change == path_to_change->end())
     return;
 
   pending_changes_.erase(found_change->second.position_in_queue);
   path_to_change->erase(found_change);
   if (path_to_change->empty())
     url_to_change_.erase(found_origin);
 }
 
 }  // namespace sync_file_system