Fix focus visibility and style for GAIA Back and Close buttons

chrome/browser/resources/chromeos/login/screen_gaia_signin.css

 /* Copyright (c) 2012 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.
  */
 
 #gaia-signin {
   height: 609px; /* Should be the same as #user-image.loading min-heigth. */
   padding: 70px 17px 69px;    /* Screen has no controls. */
   width: 722px; /* Should be the same as #user-image.loading width. */
 }
@@ skipping 51 matching lines @@
 
 .new-gaia-flow #signin-right,
 .no-right-panel #signin-right {
   display: none;
 }
 
 .custom-gaia-button {
   background: transparent none;
   background-position: center;
   background-repeat: no-repeat;
-  height: 34px;
+  border-radius: 50%;
+  height: 24px;
   position: absolute;
-  top: 0;
-  width: 34px;
+  top: 10px;
+  width: 24px;
   z-index: 1;
 }
 
+.custom-gaia-button:hover {
+  cursor: pointer;
+}
+
+.custom-gaia-button:focus {
+  background: rgba(0,0,0,.16);
+  background-position: center;
+  background-repeat: no-repeat;
+  opacity: 0.75;
+}
+
+ /* Even more specificity than button.custom-appearance:focus:focus */
+.custom-gaia-button:focus:focus:focus {
+   border-color: transparent;
+}

[Greg Levin, 2015/05/06 00:23:58]

This overrides (removes) the light blue halo which appeared around the perimeter
of the solid grey focus circle.

+
+.custom-gaia-button:active {
+  background: rgba(0,0,0,.12);
+  background-position: center;
+  background-repeat: no-repeat;
+  opacity: 1.0;
+}
+
 #close-button-item {
   background-image: url(chrome://theme/IDR_LOGIN_CLOSE_BUTTTON);
-  right: 0;
+  right: 10px;
 }
 
 html[dir=rtl] #close-button-item {
-  left: 0;
+  left: 10px;
   right: auto;
 }
 
 .loading #close-button-item,
 .new-gaia-flow .full-width #close-button-item {
   background-image: url(chrome://theme/IDR_LOGIN_CLOSE_BUTTTON_ON_WHITE);
 }
 
 .loading.auth-completed #close-button-item {
   display: none;
 }
 
 #close-button-item:disabled {
   background-image: url(chrome://theme/IDR_LOGIN_CLOSE_BUTTTON_MASKED);
 }
 
-#close-button-item:hover {
-  cursor: pointer;
-}
-
 #back-button-item {
   background-image: url(chrome://theme/IDR_LOGIN_BACK_BUTTTON);
-  left: 0;
+  left: 10px;
 }
 
 html[dir=rtl] #back-button-item {
   -webkit-transform: scaleX(-1);
   left: auto;
-  right: 0;
+  right: 10px;
 }
 
 .new-gaia-flow .full-width #back-button-item {
   display: none;
 }
 
 #back-button-item:disabled {
   background-image: url(chrome://theme/IDR_LOGIN_BACK_BUTTTON_MASKED);
 }
 
-#back-button-item:hover {
-  cursor: pointer;
-}
-
 .signin-text {
   color: #666;
   margin-top: 20px;
 }
 
 .signin-link {
   color: rgb(37, 79, 155);
   cursor: pointer;
   text-decoration: none;
 }
@@ skipping 167 matching lines @@
 
 html /deep/ #forgotPasswordDlg {
   position: fixed;
   top: 200px;
   width: 350px;
 }
 
 html /deep/ #forgotPasswordDlg gaia-paper-button[autofocus] {
   color: rgb(66, 133, 244);
 }