Modify UpdateLibrary to use async RequestUpdateCheck call

chrome/browser/chromeos/login/update_screen.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 "chrome/browser/chromeos/login/update_screen.h"
 
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/threading/thread_restrictions.h"
 #include "chrome/browser/chromeos/cros/cros_library.h"
@@ skipping 116 matching lines @@
     case UPDATE_STATUS_ERROR:
     case UPDATE_STATUS_REPORTING_ERROR_EVENT:
       ExitUpdate(REASON_UPDATE_ENDED);
       break;
     default:
       NOTREACHED();
       break;
   }
 }
 
+namespace {
+void update_callback(void* user_data, UpdateResult result, const char* msg) {

[altimofeev, 2011/03/09 10:42:27]

nit: Please, use BumpyCase for the function's name. Also, please, add comment or
use more specific function's name.

[stevenjb, 2011/03/10 01:23:16]

Oops. Relapse. Done.

+  if (result != UPDATE_RESULT_SUCCESS) {
+    DCHECK(user_data);
+    UpdateScreen* screen = static_cast<UpdateScreen*>(user_data);
+    screen->ExitUpdate(UpdateScreen::REASON_UPDATE_INIT_FAILED);

[altimofeev, 2011/03/09 10:42:27]

What if update screen has been destroyed before this callback is fired? (e.g.
user skips update).

[stevenjb, 2011/03/10 01:23:16]

Good catch. I will add an instance list to check. Shouldn't need anything fancy
since this all happens on the same thread.

+  }
+}
+}  // namespace
+
 void UpdateScreen::StartUpdate() {
   // Reset view if view was created.
   if (view()) {
     view()->Reset();
     view()->set_controller(this);
     is_downloading_update_ = false;
     view()->SetProgress(kBeforeUpdateCheckProgress);
   }
 
   if (!CrosLibrary::Get()->EnsureLoaded()) {
     LOG(ERROR) << "Error loading CrosLibrary";
     ExitUpdate(REASON_UPDATE_INIT_FAILED);
   } else {
     CrosLibrary::Get()->GetUpdateLibrary()->AddObserver(this);
     VLOG(1) << "Initiate update check";
-    if (!CrosLibrary::Get()->GetUpdateLibrary()->CheckForUpdate()) {
-      ExitUpdate(REASON_UPDATE_INIT_FAILED);
-    }
+    CrosLibrary::Get()->GetUpdateLibrary()->RequestUpdate(
+        update_callback, this);
   }
 }
 
 void UpdateScreen::CancelUpdate() {
   // Screen has longer lifetime than it's view.
   // View is deleted after wizard proceeds to the next screen.
   if (view())
     ExitUpdate(REASON_UPDATE_CANCELED);
 }
 
@@ skipping 84 matching lines @@
   // TODO(dpolukhin): Analyze file content. Now we can just assume that
   // if the file exists and not empty, there is critical update.
   return true;
 }
 
 void UpdateScreen::SetAllUpdatesCritical(bool is_critical) {
   is_all_updates_critical_ = is_critical;
 }
 
 }  // namespace chromeos