Added help text to PeerConnection test page.

chrome/test/data/webrtc/manual/peerconnection.html

Index: chrome/test/data/webrtc/manual/peerconnection.html
diff --git a/chrome/test/data/webrtc/manual/peerconnection.html b/chrome/test/data/webrtc/manual/peerconnection.html
index a57d72a0a9f22ec684f24a40308276e34ee46d46..93bb151920c2f4de77e0ea09f4f48e3aeef9fc91 100644
--- a/chrome/test/data/webrtc/manual/peerconnection.html
+++ b/chrome/test/data/webrtc/manual/peerconnection.html
@@ -95,6 +95,77 @@
       <td valign="top"><pre id="messages"></pre></td>
       <td valign="top"><pre id="debug"></pre></td>
     </tr>
+    <tr>
+      <td><button onclick="toggleHelp();">Toggle Help</button></td>
+    </tr>
+    <tr>
+      <td id="help" style="display: none" colspan="2">
+        <h1>How This Page Works</h1>
+        <p>
+          This page is intended for testing WebRTC calls.
+
+          This is how you set up a normal call:
+        </p>
+        <ol>
+          <li>Open this page in two tabs.</li>
+          <li>Start the peerconnection server. Click on the question mark next
+            to the 'server' field for instruction on how to do that. The easiest
+            thing is to start it on localhost, but you can start it on any
+            machine you like and connect to hostname:8888.</li>
+          <li>Click the Connect button in both tabs.</li>
+          <li>Click the Call button in one of the tabs. You should see a bunch
+            of printouts when this happens. Note that no streams are sent to
+            begin with.</li>
+          <li>Grant media access using the checkboxes and Request button.</li>
+          <li>Send the local stream by clicking the "Send" button, in both tabs.
+            </li>
+          <li>You should now have a call up and both sides should be receiving
+            media data (depending on what access you granted on the respective
+            pages)</li>
+          <li>You can now choose to stop, re-request, re-send or disable streams
+            in any way you like, or hang up and re-start the call. You don't
+            need to disconnect: that's done automatically when you close the
+            page. Hanging up is NOT done automatically though.</li>
+        </ol>
+        <p>Detailed descriptions:</p>
+        <ul>
+          <li>Connect - once a connection is established, you generally won't
+            need to click this button again. Connecting really isn't something
+            related to WebRTC as such, it's just the signalling solution.</li>
+          <li>Note that if more than two users/machines have established a
+            connection to the same PC server, you will get an error when
+            pressing this button. The test is hard-coded to only allow 2 peers
+            on the server at the same time.</li>
+          <li>Pressing the Send button for local streams will in effect add
+            the current local stream, such as it is, to the current
+            peerconnection and re-negotiate the call (e.g it will send SDP
+            offers back and forth).</li>
+          <li>If you request user media again, it will overwrite the current
+            local stream with the new one. This means that pressing Send will
+            add the stream you just got from the request. The code will not
+            attempt to stop or remove the previous stream from the
+            peerconnection, so depending on peerconnection's semantics the old
+            stream will remain with the peerconnection (perhaps the streams will
+            be sent simultaneously?)</li>
+          <li>Hang Up will clear away peer connections on both sides, and a new
+            call can be started if desired. The peers remain connected to the
+            peerconnection server.</li>
+          <li>The Toggle buttons will set the .enabled properties on the first
+            video and audio track for the local or remote stream, respectively.
+            This is effectively a temporary "mute" for the streams.</li>
+          <li>Stop terminates a stream, which means it will no longer send any
+            more data.</li>
+          <li>Remove will remove the current local stream from the current
+            peerconnection. For instance, you should be able to send a stream,
+            remove it, re-request a new stream and send that within the same
+            call. Note that re-requesting user media overwrites the current
+            media stream, so the reverse is not possible.</li>
+          <li>The Constraints field can pass in arbitrary constraints. The code
+            will attempt to eval the code you write in and pass it whenever the
+            code asks for constraints. [experimental]</li>
+        </ul>
+      </td>
+    </tr>
   </table>
 
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