[WebUI] Better focus ring drawing.

Ensure that focus rings do not change width when the currently focused
button becomes disabled (due to action triggered by button)

BUG=321928
R=estade@chromium.org

Review URL: https://codereview.chromium.org/149603004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249210 0039d316-1c4b-4281-b951-d872f2087c98

ui/webui/resources/css/widgets.css

@@ -24,6 +24,7 @@ input[type='radio'] {
   color: #444;
   font: inherit;
   margin: 0 1px 0 0;
+  outline: none;
   text-shadow: 0 1px 0 rgb(240, 240, 240);
 }
 
@@ -98,6 +99,7 @@ textarea {
   /* Use min-height to accommodate addditional padding for touch as needed. */
   min-height: 2em;
   padding: 3px;
+  outline: none;
 <if expr="is_win or is_macosx or is_ios">
   /* For better alignment between adjacent buttons and inputs. */
   padding-bottom: 4px;