Move tab index and focus to radio button.

chrome/browser/resources/settings/controls/controlled_radio_button.js

Index: chrome/browser/resources/settings/controls/controlled_radio_button.js
diff --git a/chrome/browser/resources/settings/controls/controlled_radio_button.js b/chrome/browser/resources/settings/controls/controlled_radio_button.js
index 33dc95979e7ea356b9a40952cba52bb0b33ade97..cf697206d0d34ec9b661ceb0f252fcac6ccd2ee7 100644
--- a/chrome/browser/resources/settings/controls/controlled_radio_button.js
+++ b/chrome/browser/resources/settings/controls/controlled_radio_button.js
@@ -21,6 +21,10 @@ Polymer({
     },
   },
 
+  listeners: {
+    'focus': 'onFocus_',
+  },
+
   /**
    * @return {boolean} Whether the button is disabled.
    * @private
@@ -49,4 +53,9 @@ Polymer({
     e.preventDefault();
     e.stopPropagation();
   },
+
+  /** Focuses the internal radio button when the row is selected. */
+  onFocus_: function() {
+    this.$.radioButton.focus();
+  },
 });