Replace in-session header with auto-hide tool-bar.

remoting/webapp/me2mom/debug_log.css

 /* Copyright (c) 2011 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.
  */
 
 #debug-log {
   background-color: white;
   bottom: 0;
   border-top: 1px solid black;
-  display: none;
   height: 150px;
   margin: 0;
   opacity: 0.85;
-  overflow: auto;
   padding: 0;
   position: fixed;
   width: 100%;
   z-index: 100;
   -webkit-user-select: text;
 }
 
-#debug-log > p {
+#debug-messages {
+  border-top: 1px solid black;
+  overflow: auto;
+  height: inherit;
+}
+
+#debug-messages > p {
   font-family: monospace;
   font-weight: bold;
   font-size: small;
   margin: 0.35em;
   padding: 0;
 }
 
 #debug-log-toggle {
   float: right;
 }