[Chromoting] Log mouse events in remoting_key_tester

remoting/tools/javascript_key_tester/main.html

Index: remoting/tools/javascript_key_tester/main.html
diff --git a/remoting/tools/javascript_key_tester/main.html b/remoting/tools/javascript_key_tester/main.html
index a7deb422da1c962e299556648032302c2d053a32..d96d8cfd56c32af43a1e6703b2ba5b4727fd5b03 100644
--- a/remoting/tools/javascript_key_tester/main.html
+++ b/remoting/tools/javascript_key_tester/main.html
@@ -19,9 +19,11 @@ found in the LICENSE file.
       <button id="show-log">Debug log</button>
       <button id="clear-log">Clear logs</button>
     </div>
+    <h4>Try mouse events in the gray area below.</h4>
     <div id="pnacl-listener">
-      <embed id="pnacl-plugin" width=0 height=0
-             src="remoting_key_tester.nmf" type="application/x-pnacl" />
+      <embed id="pnacl-plugin"
+             src="remoting_key_tester.nmf"
+             type="application/x-pnacl" />
     </div>
     <div class="logs">
       <div id="pnacl-log" class="summary-log-container">