Update color/thickness of ChromeOS login shelf button focus state.

ui/login/oobe.css

Index: ui/login/oobe.css
diff --git a/ui/login/oobe.css b/ui/login/oobe.css
index 809f2e80e30ab47a0eacc297b6b3d5f7483e93bf..0309ec0633b910686136f8181094717351bf5daa 100644
--- a/ui/login/oobe.css
+++ b/ui/login/oobe.css
@@ -37,14 +37,14 @@ button {
 button.custom-appearance:not(.button-restricted):not(.button-fancy):not(
     [is="gaia-icon-button"]) {
   -webkit-transition: border-color 200ms;
-  border: 1px solid transparent;
+  border: 2px solid transparent;
   /* Don't grey out disabled buttons. */
   color: buttontext !important;
 }
 
 /* ':focus' used three times to increase specificity. */
 button.custom-appearance:focus:focus:focus {
-  border-color: rgb(77, 144, 254);
+  border-color: rgba(66, 133, 244, 0.6); /* #4285f4 */
 }
 
 button:not(.custom-appearance) {