Remove dead code for system VK.

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

Index: ui/keyboard/resources/elements/kb-altkey-set.html
diff --git a/ui/keyboard/resources/elements/kb-altkey-set.html b/ui/keyboard/resources/elements/kb-altkey-set.html
deleted file mode 100644
index dd471792eea64fafa38c53efc6e369298450ef1c..0000000000000000000000000000000000000000
--- a/ui/keyboard/resources/elements/kb-altkey-set.html
+++ /dev/null
@@ -1,23 +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-set" attributes="offset char"
-    on-pointerout="{{out}}">
-  <template>
-    <style>
-      :host {
-        -webkit-box-shadow: 0 0 12px 5px rgba(204, 204, 204, 0.65),
-            0 3px 4px 4px rgba(136, 136, 136, 0.65);
-         background-color: #ffffff;
-         border-radius: 2px;
-         display: -webkit-box;
-         text-align: center;
-         position: absolute;
-      }
-    </style>
-    <content select="*"></content>
-  </template>
-</polymer-element>