ChromeOS OOBE: display icons specific to screen DPI.

chrome/browser/resources/chromeos/login/oobe_buttons.html

Index: chrome/browser/resources/chromeos/login/oobe_buttons.html
diff --git a/chrome/browser/resources/chromeos/login/oobe_buttons.html b/chrome/browser/resources/chromeos/login/oobe_buttons.html
index df4e93e19f588ccecab71b932c4adc1aab952f9d..6e5c3843e54e33ad244403971f05173438ffebc2 100644
--- a/chrome/browser/resources/chromeos/login/oobe_buttons.html
+++ b/chrome/browser/resources/chromeos/login/oobe_buttons.html
@@ -98,7 +98,9 @@
     </oobe-welcome-secondary-button>
 
   Attributes:
-    'icon' - a name of icon from material design set to show on button.
+    1x and 2x icons:
+      'icon1x' - a name of icon from material design set to show on button.
+      'icon2x' - a name of icon from material design set to show on button.
     'label-for-aria' - accessibility label.
 -->
 <dom-module id="oobe-welcome-secondary-button">
@@ -108,7 +110,10 @@
       <div id="container" class="flex layout vertical center self-stretch">
         <div id="subcontainer"
             class="flex layout horizontal center self-stretch">
-          <iron-icon icon="[[icon]]" class="oobe-icon"></iron-icon>
+          <iron-icon id="icon1x" icon="[[icon1x]]" class="oobe-icon">
+          </iron-icon>
+          <iron-icon id="icon2x" icon="[[icon2x]]" class="oobe-icon">
+          </iron-icon>
           <content></content>
         </div>
       </div>