Merge pull request #310 from youennf/add-deviceId-setting-capability

Add deviceId as settings and constraints for screen share video tracks.

index.html

@@ -793,6 +793,26 @@ <h2 id="constrainable-properties">Constrainable Properties for Captured
           </tr>
 
 
+          <tr id="def-constraint-deviceId">
+            <td><dfn class="export">deviceId</dfn>
+            </td>
+
+            <td>{{DOMString}}</td>
+
+            <td>
+              The identifier of the surface being captured.
+
+              <p>As a setting, identifies the [=display surface=] that
+              is being captured. The identifier MUST be uniquely generated for
+              each [=document=].</p>
+
+              <p>As a capability, the setting value MUST be the lone value
+              present, rendering this property immutable from the application
+              viewpoint.</p>
+            </td>
+          </tr>
+
+
           <tr id="def-constraint-displaySurface">
             <td><dfn class="export">displaySurface</dfn>
             </td>