Adding an alternate keyset to .com

ui/keyboard/resources/layouts/symbol-altkeys.js

 // Copyright 2013 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.
 
 var symbolAltKeys = {
   '1': ['\u00B9', // Superscript 1
         '\u00BD', // Vulgar fraction 1/2
         '\u2153', // Vulgar fraction 1/3
         '\u00BC', // Vulgar fraction 1/4
         '\u215B'], // Vulgar fraction 1/8
@@ skipping 18 matching lines @@
   '\\': ['/'],
   '"': ['\u201C', // Left double quote
         '\u201D', // Right double quote
         '\u201E', // Double low-9 quotation mark
         '\u00AB', // Left double angle quote
         '\u00BB'], // Right double angle quote
   '-': ['_'],
   '!': ['\u00A1'], // Inverted exclamation mark
   '?': ['\u00BF'], // Inverted question mark
   '(': ['<', '{', '['],
-  ')': ['>', '}', ']']
+  ')': ['>', '}', ']'],
+  '.com' : ['.net','.org','.gov']
 };
 
 document.addEventListener('WebComponentsReady', function() {
   var altkeyMetadata = document.createElement('kb-altkey-data');
   altkeyMetadata.registerAltkeys(symbolAltKeys);
 });