Add new chrome://proximity-auth WebUI for debugging Smart Lock.

components/proximity_auth/webui/resources/proximity_auth.css

Index: components/proximity_auth/webui/resources/proximity_auth.css
diff --git a/chrome/browser/resources/gaia_auth/main.css b/components/proximity_auth/webui/resources/proximity_auth.css
similarity index 63%
copy from chrome/browser/resources/gaia_auth/main.css
copy to components/proximity_auth/webui/resources/proximity_auth.css
index 397947616e688a738e064017c297dfbd0426ea84..25ecca35154bd0e8d2f43fdd5e3e9a0ff5da6237 100644
--- a/chrome/browser/resources/gaia_auth/main.css
+++ b/components/proximity_auth/webui/resources/proximity_auth.css
@@ -1,25 +1,19 @@
-/* Copyright 2013 The Chromium Authors. All rights reserved.
+/* Copyright 2015 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.
  */
 
 html,
-body,
-iframe {
+body {
+  width: 100%;
   height: 100%;
   margin: 0;
   padding: 0;
-  width: 100%;
-}
-
-iframe {
   overflow: hidden;
 }
 
-webview {
-  display: inline-block;
+canvas {
+  width: 100%;
   height: 100%;
   margin: 0;
-  padding: 0;
-  width: 100%;
 }