Add mojo web UI framework based on Nat's TVCM

mojo/spy/ui/spy_shell.html

+<!--
+Copyright 2014 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.
+-->
+<style>
+  html, body {
+    margin: 0;
+    padding: 0;
+    width: 100%;
+    height: 100%;
+    display: -webkit-flex;
+    -webkit-flex-direction: column;
+  }
+  body > x-spy-shell {
+    -webkit-flex: 1 1 auto;
+  }
+
+  x-spy-shell {
+    display: -webkit-flex;
+    -webkit-flex-direction: column;
+  }
+
+  x-spy-shell > #status {
+    -webkit-flex: 0 0 auto;
+    border-bottom: 1px solid black;
+  }
+
+  x-spy-shell > x-spy {
+    -webkit-flex: 1 1 auto;
+  }
+</style>
+
+
+<template id="x-spy-shell-template">
+  <div id="status"></div>
+  <x-spy></x-spy>
+</template>
+