Adds support for DELETE,BACKSPACE,ENTER,SPACE keys on single iframe ntp.

chrome/browser/resources/local_ntp/most_visited_single.js

 /* 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. */
 
  // Single iframe for NTP tiles.
 (function() {
 'use strict';
 
 
 /**
@@ skipping 320 matching lines @@
   var html = [];
   if (!USE_ICONS) {
     html.push('<div class="mv-favicon"></div>');
   }
   html.push('<div class="mv-title"></div><div class="mv-thumb"></div>');
   html.push('<div title="' + tooltip + '" class="mv-x"></div>');
   tile.innerHTML = html.join('');
 
   tile.href = data.url;
   tile.title = data.title;
-  tile.addEventListener('keypress', function(ev) {
-    if (ev.keyCode == 127) { // DELETE
+  tile.addEventListener('keydown', function(event) {
+    if (event.keyCode == 46 /* DELETE */ ||
+        event.keyCode == 8 /* BACKSPACE */) {
+      event.preventDefault();
+      event.stopPropagation();
       blacklistTile(tile);
-      ev.stopPropagation();
-      return false;
+    } else if (event.keyCode == 13 /* ENTER */ ||
+               event.keyCode == 32 /* SPACE */) {
+      event.preventDefault();
+      tile.click();
     }
   });
   // TODO(fserb): remove this or at least change to mouseenter.
   tile.addEventListener('mouseover', function() {
     logEvent(LOG_TYPE.NTP_MOUSEOVER);
   });
 
   var title = tile.querySelector('.mv-title');
   title.innerText = data.title;
   title.style.direction = data.direction || 'ltr';
@@ skipping 163 matching lines @@
     var html = document.querySelector('html');
     html.dir = 'rtl';
   }
 
   window.addEventListener('message', handlePostMessage);
 };
 
 
 window.addEventListener('DOMContentLoaded', init);
 })();