favor DCHECK_CURRENTLY_ON for better logs in chrome/browser/chromeos/

chrome/browser/chromeos/login/screens/user_image_screen.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/login/screens/user_image_screen.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 82 matching lines @@
     image_decoder_->set_delegate(NULL);
 }
 
 void UserImageScreen::OnScreenReady() {
   is_screen_ready_ = true;
   if (!IsWaitingForSync())
     HideCurtain();
 }
 
 void UserImageScreen::OnPhotoTaken(const std::string& raw_data) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
   user_photo_ = gfx::ImageSkia();
   if (image_decoder_.get())
     image_decoder_->set_delegate(NULL);
   image_decoder_ = new ImageDecoder(this, raw_data,
                                     ImageDecoder::DEFAULT_CODEC);
   scoped_refptr<base::MessageLoopProxy> task_runner =
       BrowserThread::GetMessageLoopProxyForThread(BrowserThread::UI);
   image_decoder_->Start(task_runner);
 }
 
@@ skipping 231 matching lines @@
 
 void UserImageScreen::ExitScreen() {
   policy_registrar_.reset();
   sync_timer_.reset();
   if (UserImageSyncObserver* sync_observer = GetSyncObserver())
     sync_observer->RemoveObserver(this);
   Finish(BaseScreenDelegate::USER_IMAGE_SELECTED);
 }
 
 }  // namespace chromeos