Fix login visual hitch on chromebook

chrome/browser/ui/app_list/search_builder.cc

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright (c) 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/ui/app_list/search_builder.h"
 
 #include <string>
 #include <vector>
 
 #include "base/command_line.h"
 #include "chrome/browser/autocomplete/autocomplete_classifier.h"
@@ skipping 235 matching lines @@
             *bundle.GetImageSkiaNamed(IDR_CONTACT_ACTION_EMAIL),
             *bundle.GetImageSkiaNamed(IDR_CONTACT_ACTION_EMAIL_H),
             *bundle.GetImageSkiaNamed(IDR_CONTACT_ACTION_EMAIL),
             l10n_util::GetStringUTF16(IDS_APP_LIST_CONTACT_EMAIL_TOOLTIP)));
     SetActionIcons(icons);
   }
 
  protected:
   // Overridden from SearchBuilderResult:
   virtual void UpdateIcon() OVERRIDE {
+    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
     const contacts::Contact* contact = GetContact();
     if (contact && contact->has_raw_untrusted_photo()) {
       photo_decoder_ =
           new ImageDecoder(
               this,
               contact->raw_untrusted_photo(),
               ImageDecoder::DEFAULT_CODEC);
-      photo_decoder_->Start();
+      scoped_refptr<base::MessageLoopProxy> task_runner =
+          BrowserThread::GetMessageLoopProxyForThread(BrowserThread::UI);
+      photo_decoder_->Start(task_runner);
     } else {
       SetIcon(
           *ui::ResourceBundle::GetSharedInstance().GetImageSkiaNamed(
               IDR_CONTACT_DEFAULT_PHOTO));
     }
   }
 
  private:
   // Overridden from ImageDecoder::Delegate:
   virtual void OnImageDecoded(const ImageDecoder* decoder,
@@ skipping 163 matching lines @@
     result->Init(profile_, *it);
     results_->Add(result);
   }
 }
 
 void SearchBuilder::OnResultChanged(bool default_match_changed) {
   // TODO(xiyuan): Handle default match properly.
   const AutocompleteResult& ac_result = controller_->result();
   PopulateFromACResult(ac_result);
 }