Show third party wallpaper app name in wallpaper picker

chrome/browser/resources/chromeos/wallpaper_manager/css/wallpaper_manager.css

 /* 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. */
 
 html {
   height: 100%;
 }
 
 body {
   -webkit-app-region: drag;
@@ skipping 143 matching lines @@
   -webkit-animation-iteration-count: infinite;
   -webkit-animation-name: spin;
   -webkit-animation-timing-function: linear;
   background-image: url('../images/ui/spinner.png');
   background-position: center;
   background-repeat: no-repeat;
   height: 16px;
   width: 16px;
 }
 
+#wallpaper-set-by-message {
+  -webkit-padding-end: 5px;
+  -webkit-padding-start: 15px;
+  height: 17px;
+}
+
+#wallpaper-set-by-message[hidden] + .image-picker {

[flackr, 2014/06/17 15:20:34]

Instead of hardcoding these sizes, can you use a box flex layout to size the
.image-picker to be the available space?

[bshe, 2014/06/17 19:01:43]

Done. I remember having some scrolling issues when set the wallpaper webui grid
to flex box. But it no longer reproduce.

+  height: 287px;
+}
+
 .image-picker {
   -webkit-padding-end: 5px;
   -webkit-padding-start: 15px;
   display: block;
   /* Set font size to 0 to remove the extra vertical margin between two rows of
    * thumbnails.
    * TODO(bshe): Find the root cause of the margin.
    */
   font-size: 0;
-  height: 287px;
+  height: 270px;
   outline: none;
   overflow-y: auto;
   padding-bottom: 15px;
   padding-top: 5px;
 }
 
 .image-picker .spacer {
   display: block;
 }
 
@@ skipping 191 matching lines @@
   margin-right: 4px;
   opacity: 0.7;
   position: relative;
   top: 4px;
   width: 17px;
 }
 
 #surprise-me #checkbox.checked {
   background-image: url('../images/ui/checkbox_checked.png');
 }