[NTP] Hide focus on animated Doodles

Doodles only need a focus ring when tabbed to but not when clicked.

Bug: 778247
Change-Id: Ida0556ae6f03f272d576d76d0842ae3ca42afa57
Reviewed-on: https://chromium-review.googlesource.com/1241313Reviewed-by: Kristi Park <kristipark@chromium.org>
Commit-Queue: Kyle Milka <kmilka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#593696}

chrome/browser/resources/local_ntp/local_ntp.css

@@ -150,6 +150,10 @@ body.hide-fakebox #fakebox {
   display: block;
 }
 
+#logo-doodle-image {
+  outline: none;
+}
+
 #logo-default.fade,
 #logo-doodle.fade {
   transition: opacity 130ms, visibility 130ms;

chrome/browser/resources/local_ntp/local_ntp.html

@@ -36,7 +36,7 @@
       <!-- A doodle, if any: its link and image. -->
       <div id="logo-doodle">
         <button id="logo-doodle-button">
-          <img id="logo-doodle-image"></img>
+          <img id="logo-doodle-image" tabindex="-1"></img>
         </button>
         <iframe id="logo-doodle-iframe" scrolling="no"></iframe>
         <!-- A spinner, visible on dark-themed NTPs, prompting the doodle -->