Fixes alignment of spacebar row.

ui/keyboard/resources/layouts/qwerty.html

 <!--
   -- 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.
   -->
 
 <template>
   <kb-keyset id="qwerty-upper" align="stretch">
     <kb-row>
       <kb-key-sequence keys="QWERTYUIOP" hintTexts="1234567890">
       </kb-key-sequence>
       <kb-key class="dark" char="&#x0008;" repeat stretch align="right"
           weight="110">backspace</kb-key>
     </kb-row>
     <kb-row align="right">
       <kb-key-sequence keys="ASDFGHJKL"></kb-key-sequence>
       <kb-key class="dark" char="&#x000A;" align="right"
           weight="175">enter</kb-key>
     </kb-row>
     <kb-row>
       <kb-shift-key weight="105" align="left">shift</kb-shift-key>
       <kb-key-sequence keys="ZXCVBNM!?"></kb-key-sequence>
       <kb-shift-key weight="105" stretch align="right">shift</kb-shift-key>
     </kb-row>
     <kb-row>
       <kb-key class="dark" toKeyset="down:symbol" char="Invalid"
           align="left" weight="105">?123</kb-key>
       <kb-key class="dark">_</kb-key>
-      <kb-key class="dark">/</kb-key>
+      <kb-key class="dark" stretch>/</kb-key>
       <kb-key char=" " class="space" weight="540"></kb-key>
       <kb-key class="dark">,</kb-key>
       <kb-key class="dark">.</kb-key>
       <kb-hide-keyboard-key stretch weight="105">hide</kb-hide-keyboard-key>
     </kb-row>
     <kb-altkey-container hidden>
     </kb-altkey-container>
   </kb-keyset>
 
   <kb-keyset id="qwerty-lower" isDefault=true align="stretch">
@@ skipping 10 matching lines @@
     </kb-row>
     <kb-row>
       <kb-shift-key weight="105" align="left">shift</kb-shift-key>
       <kb-key-sequence keys="zxcvbnm!?"></kb-key-sequence>
       <kb-shift-key stretch weight="105" align="right">shift</kb-shift-key>
     </kb-row>
     <kb-row>
       <kb-key class="dark" toKeyset="down:symbol" char="Invalid"
           align="left" weight="105">?123</kb-key>
       <kb-key class="dark">_</kb-key>
-      <kb-key class="dark">/</kb-key>
+      <kb-key class="dark" stretch>/</kb-key>
       <kb-key char=" " class="space" weight="540"></kb-key>
       <kb-key class="dark">,</kb-key>
       <kb-key class="dark">.</kb-key>
       <kb-hide-keyboard-key stretch weight="105">hide</kb-hide-keyboard-key>
     </kb-row>
     <kb-altkey-container hidden>
     </kb-altkey-container>
   </kb-keyset>
 
   <kb-keyset id="qwerty-symbol" align="stretch">
@@ skipping 10 matching lines @@
     <kb-row>
       <kb-key class="dark" toKeyset="down:more" char="Invalid" align="left"
           weight="105">~[&lt;</kb-key>
       <kb-key-sequence keys="\=*&quot;':;!?"></kb-key-sequence>
       <kb-key class="dark" toKeyset="down:more" char="Invalid" align="right"
           stretch weight="105">~[&lt;</kb-key>
     </kb-row>
     <kb-row>
       <kb-abc-key align="left" weight="105">ABC</kb-abc-key>
       <kb-key class="dark">_</kb-key>
-      <kb-key class="dark">/</kb-key>
+      <kb-key class="dark" stretch>/</kb-key>
       <kb-key char=" " class="space" weight="540"></kb-key>
       <kb-key class="dark">,</kb-key>
       <kb-key class="dark">.</kb-key>
       <kb-hide-keyboard-key stretch weight="105">hide</kb-hide-keyboard-key>
     </kb-row>
     <kb-altkey-container hidden>
     </kb-altkey-container>
   </kb-keyset>
 
   <kb-keyset id="qwerty-more" align="stretch">
@@ skipping 16 matching lines @@
           align="left" weight="105">?123</kb-key>
       <kb-key-sequence
           keys="\&#x00A9;&#x00AE;&#x2122;&#8453;[]&iexcl;&iquest;">
       </kb-key-sequence>
       <kb-key stretch class="dark" toKeyset="down:symbol" char="Invalid"
           align="right" weight="105">?123</kb-key>
     </kb-row>
     <kb-row>
       <kb-abc-key align="left" weight="105">ABC</kb-abc-key>
       <kb-key class="dark">&lt;</kb-key>
-      <kb-key class="dark">&gt;</kb-key>
+      <kb-key class="dark" stretch>&gt;</kb-key>
       <kb-key char=" " class="space" weight="540"></kb-key>
       <kb-key class="dark">,</kb-key>
       <kb-key class="dark">.</kb-key>
-      <kb-hide-keyboard-key weight="105">hide</kb-hide-keyboard-key>
+      <kb-hide-keyboard-key stretch weight="105">hide</kb-hide-keyboard-key>
     </kb-row>
   </kb-keyset>
 </template>