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 15 matching lines @@
 #author-website,
 /* TODO(bshe): Once http://crbug.com/369651 fixed, use .image-picker instead of
  * #category-container.
  */
 #category-container,
 #surprise-me {
   -webkit-app-region: no-drag;
 }
 
 .dialog-container {
-  -webkit-box-orient: vertical;
-  display: -webkit-box;
+  display: flex;
+  flex-direction: column;
+  height: 100%;
   overflow: hidden;
 }
 
 .dialog-topbar {
   -webkit-box-align: center;
   display: -webkit-box;
   height: 54px;
   overflow: hidden;
   padding: 0 15px;
   position: relative;
@@ skipping 61 matching lines @@
 
 #bar {
   -webkit-transition: left 130ms ease-in-out;
   background-color: #eee;
   height: 4px;
   position: absolute;
   top: 0;
 }
 
 .dialog-main {
-  -webkit-box-align: stretch;
-  -webkit-box-flex: 1;
-  display: -webkit-box;
+  display: flex;
+  flex: 1;
 }
 
 #category-container {
-  -webkit-box-flex: 1;
-  -webkit-box-orient: vertical;
-  display: -webkit-box;
+  display: flex;
+  flex: 1;
+  flex-direction: column;
   position: relative;
 }
 
 #spinner-container {
   -webkit-box-align: center;
   -webkit-box-pack: center;
   display: -webkit-box;
   height: 287px;
   padding-bottom: 15px;
   padding-top: 5px;
@@ skipping 16 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:empty {
+  display: none;
+}
+
 .image-picker {
   -webkit-padding-end: 5px;
   -webkit-padding-start: 15px;
   display: block;
+  flex: 1;
   /* 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;
   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');
 }