Alternative fix for #322.

getusermedia.html

@@ -1217,7 +1217,7 @@ <h2>Constrainable Properties</h2>
               <td><dfn>groupId</dfn></td>
               <td>DOMString</td>
               <td>
-                The origin-unique group identifier for the source of the
+                The origin and browsing session unique group identifier for the source of the
                 <a>MediaStreamTrack</a>. Two devices have the same group
                 identifier if they belong to the same physical device; for
                 example, the audio input and output devices representing the
@@ -2434,13 +2434,7 @@ <h2>Device Info</h2>
           devices have the same group identifier if they belong to the same
           physical device; for example a monitor with a built-in camera and
           microphone.</p>
-          <p class="fingerprint">Since <code>groupId</code> may persist across
-          browsing sessions and to reduce its potential as a fingerprinting
-          mechanism, <code>groupId</code> is to be treated as other persistent
-          storage mechanisms such as cookies [[COOKIES]]. User agents MUST
-          reset per-origin device identifiers when other persistent storages
-          are cleared.</p>
-        </dd>
+       </dd>
         <dt>serializer = { attribute }</dt>
       </dl>
       <dl class="idl" title="enum MediaDeviceKind">
@@ -3930,9 +3924,9 @@ <h1>Privacy and Security Considerations</h1>
     identifiers for the devices are designed to not be useful for a fingerprint
     that can track the user between origins, but the number and grouping of
     devices adds to the fingerprint surface. It recommends to treat the
-    per-origin persistent identifier <code>deviceId</code> and
-    <code>groupId</code> as other persistent storages (e.g. cookies) are
-    treated.</p>
+    per-origin persistent identifier <code>deviceId</code> as other persistent
+    storages (e.g. cookies) are treated.</p>
+
     <p>When authorization is given, this document describes how to get access
     to, and use, media data from the devices mentioned. This data may be
     sensitive; advice is given that indicators should be supplied to indicate