Add support for transparent/translucent pixels in the user image

chrome/browser/chromeos/login/supervised/supervised_user_creation_screen.cc

 // Copyright 2014 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/supervised/supervised_user_creation_screen.h"
 
 #include <utility>
 
 #include "ash/common/shelf/wm_shelf.h"
 #include "ash/common/wallpaper/wallpaper_controller.h"
@@ skipping 481 matching lines @@
   UserImageManager* image_manager =
       ChromeUserManager::Get()->GetUserImageManager(
           AccountId::FromUserEmail(user_id));
   switch (selected_image_) {
     case user_manager::User::USER_IMAGE_EXTERNAL:
       // Photo decoding may not have been finished yet.
       if (user_photo_.isNull()) {
         apply_photo_after_decoding_ = true;
         return;
       }
-      image_manager->SaveUserImage(
-          user_manager::UserImage::CreateAndEncode(user_photo_));
+      image_manager->SaveUserImage(user_manager::UserImage::CreateAndEncode(
+          user_photo_, user_manager::UserImage::FORMAT_JPEG));
       break;
     case user_manager::User::USER_IMAGE_PROFILE:
       NOTREACHED() << "Supervised users have no profile pictures";
       break;
     default:
       DCHECK(selected_image_ >= 0 &&
              selected_image_ < default_user_image::kDefaultImagesCount);
       image_manager->SaveUserDefaultImageIndex(selected_image_);
       break;
   }
@@ skipping 115 matching lines @@
     selected_image_ = user_manager::User::USER_IMAGE_EXTERNAL;
   } else {
     NOTREACHED() << "Unexpected image type: " << image_type;
   }
 }
 
 void SupervisedUserCreationScreen::OnImageAccepted() {
 }
 
 }  // namespace chromeos