Remove dead code for system VK.

ui/keyboard/resources/elements/kb-altkey.html

Index: ui/keyboard/resources/elements/kb-altkey.html
diff --git a/ui/keyboard/resources/elements/kb-altkey.html b/ui/keyboard/resources/elements/kb-altkey.html
deleted file mode 100644
index 1d4cc4ed69e15d95947afaa0c24244bed424cafa..0000000000000000000000000000000000000000
--- a/ui/keyboard/resources/elements/kb-altkey.html
+++ /dev/null
@@ -1,56 +0,0 @@
-<!--
-  -- 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.
-  -->
-
-<polymer-element name="kb-altkey" attributes="char" on-pointerover="{{over}}"
-    on-pointerout="{{out}}" on-pointerup="{{up}}">
-  <template>
-    <style>
-      :host {
-        -webkit-box-flex: 1;
-        background-position: center center;
-        background-repeat: no-repeat;
-        background-size: contain;
-        display: -webkit-box;
-        position: relative;
-      }
-
-      :host(.active) {
-        background-color: #dddddd
-      }
-
-      :host(:first-child) {
-        border-top-left-radius: 2px;
-        border-bottom-left-radius: 2px;
-      }
-
-      :host(:not(:first-child)) .key{
-        border-left: solid 2px #dddddd;
-      }
-
-      :host(:last-child) {
-        border-top-right-radius: 2px;
-        border-bottom-right-radius: 2px;
-      }
-
-      :host .key {
-        bottom: 0;
-        color: #666666;
-        font-family: roboto-bold;
-        font-weight: 100;
-        height: 1.2em;
-        left: 0;
-        margin: auto;
-        position: absolute;
-        right: 0;
-        top: 0;
-        text-align: center;
-      }
-    </style>
-    <div class="key">
-      <content></content>
-    </div>
-  </template>
-</polymer-element>