[Chromoting] Log mouse events in remoting_key_tester

remoting/tools/javascript_key_tester/main.css

 /* Copyright (c) 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.
  */
 
 body {
   height: calc(100% - 12px);
   overflow: auto;
 }
 
@@ skipping 16 matching lines @@
   box-shadow: 0px 4px 10px 4px rgba(0,0,0,0.3);
   background-color: white;
   overflow: scroll;
 }
 
 #text-log {
   padding: 8px;
 }
 
 #pnacl-listener {
-  height: 0;
+  height: 100px;
+}
+
+#pnacl-plugin {
+  height: 100%;
+  width: 100%;
+  background-color: gray;
 }
 
 .selectable {
   -webkit-user-select: text;
   cursor: text;
 }
 
 .key-div {
   border-radius: 4px;
   border: 1px solid rgba(0, 0, 0, 0.3);
@@ skipping 45 matching lines @@
 
 .chord-div.some-keys-still-pressed::after {
   content: " \2716";  /* cross */
   color: red;
 }
 
 .controls {
   position: absolute;
   right: 8px;
   top: 8px;
-}
+}