settings: Make DeviceOAuth2TokenServiceFactory::Get() async

chrome/browser/chromeos/settings/device_oauth2_token_service_factory.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/chromeos/settings/device_oauth2_token_service_factory.h"
 
+#include "base/message_loop/message_loop.h"
+#include "base/tracked_objects.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/settings/device_oauth2_token_service.h"
 #include "chrome/browser/chromeos/settings/token_encryptor.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace chromeos {
+namespace {
 
-static DeviceOAuth2TokenService* g_device_oauth2_token_service_ = NULL;
+DeviceOAuth2TokenServiceFactory* g_factory = NULL;
 
-DeviceOAuth2TokenServiceFactory::DeviceOAuth2TokenServiceFactory() {
+}  // namespace
+
+DeviceOAuth2TokenServiceFactory::DeviceOAuth2TokenServiceFactory()
+    : token_service_(new DeviceOAuth2TokenService(
+        g_browser_process->system_request_context(),
+        g_browser_process->local_state(),
+        new CryptohomeTokenEncryptor)) {
+}
+
+DeviceOAuth2TokenServiceFactory::~DeviceOAuth2TokenServiceFactory() {
+  delete token_service_;
 }
 
 // static
-DeviceOAuth2TokenService* DeviceOAuth2TokenServiceFactory::Get() {
+void DeviceOAuth2TokenServiceFactory::Get(const GetCallback& callback) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-  return g_device_oauth2_token_service_;
+
+  DeviceOAuth2TokenService* token_service = NULL;
+  if (g_factory)
+    token_service = g_factory->token_service_;
+
+  // TODO(satorux): Implement async initialization logic for

[pastarmovj, 2013/10/23 08:02:17]

I think it makes sense to have a bug number referenced here since this seems
like a major chunk that is still missing.

[satorux1, 2013/10/24 01:49:26]

good idea. done.

+  // DeviceOAuth2TokenService. Here's how that should work:
+  //
+  // if token_service is ready:
+  //   run callback asynchronously via MessageLoop
+  //   return
+  //
+  // add callback to the pending callback list
+  //
+  // if there is only one pending callback:
+  //   start getting the system salt asynchronously...
+  //
+  // upon receiving the system salt:
+  //   create CryptohomeTokenEncryptor with that key
+  //   create DeviceOAuth2TokenService
+  //   run all the pending callbacks
+  base::MessageLoop::current()->PostTask(
+      FROM_HERE,
+      base::Bind(callback, token_service));
 }
 
 // static
 void DeviceOAuth2TokenServiceFactory::Initialize() {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-  DCHECK(!g_device_oauth2_token_service_);
-  g_device_oauth2_token_service_ = new DeviceOAuth2TokenService(
-      g_browser_process->system_request_context(),
-      g_browser_process->local_state(),
-      new CryptohomeTokenEncryptor);
+
+  DCHECK(!g_factory);
+  g_factory = new DeviceOAuth2TokenServiceFactory;
 }
 
 // static
 void DeviceOAuth2TokenServiceFactory::Shutdown() {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-  if (g_device_oauth2_token_service_) {
-    delete g_device_oauth2_token_service_;
-    g_device_oauth2_token_service_ = NULL;
+
+  if (g_factory) {
+    delete g_factory;
+    g_factory = NULL;
   }
 }
 
 }  // namespace chromeos