timestamps needed for circuit breakers and a/v sync. (#211)

* timestamps need for #61

* addressing feedback comments from @jan-ivar and @taylor-b

Author: vr000m

webrtc-stats.html

@@ -1036,8 +1036,9 @@ <h3>
         </p>
         <div>
           <pre class="idl">dictionary RTCInboundRTPStreamStats : RTCReceivedRTPStreamStats {
-             DOMString          remoteId;
-             unsigned long      framesDecoded;
+             DOMString            remoteId;
+             unsigned long        framesDecoded;
+             DOMHighResTimeStamp  lastPacketReceivedTimestamp;
 };</pre>
           <section>
             <h2>
@@ -1066,6 +1067,15 @@ <h2>
                   [[!MEDIA-SOURCE]].
                 </p>
               </dd>
+              <dt>
+                <dfn><code>lastPacketReceivedTimestamp</code></dfn> of type <span class=
+                "idlMemberType"><a>DOMHighResTimeStamp</a></span>
+              </dt>
+              <dd>
+                <p>
+                  Represents the timestamp at which the last packet was received for this SSRC. This differs from <code>timestamp</code>, which represents the time at which the statistics were generated by the local endpoint.
+                </p>
+              </dd>
             </dl>
           </section>
         </div>
@@ -1192,10 +1202,12 @@ <h3>
         </p>
         <div>
           <pre class="idl">dictionary RTCOutboundRTPStreamStats : RTCSentRTPStreamStats {
-             DOMString          remoteId;
-             double             targetBitrate;
-             unsigned long      framesEncoded;
-             double             totalEncodeTime;
+             DOMString            remoteId;
+             DOMHighResTimeStamp  lastPacketSentTimestamp;
+             double               targetBitrate;
+             unsigned long        framesEncoded;
+             double               totalEncodeTime;
+             double               averageRTCPInterval;
 };</pre>
           <section>
             <h2>
@@ -1214,6 +1226,15 @@ <h2>
                   the same SSRC.
                 </p>
               </dd>
+              <dt>
+                <dfn><code>lastPacketSentTimestamp</code></dfn> of type <span class=
+                "idlMemberType"><a>DOMHighResTimeStamp</a></span>
+              </dt>
+              <dd>
+                <p>
+                  Represents the timestamp at which the last packet was sent for this SSRC. This differs from <code>timestamp</code>, which represents the time at which the statistics were generated by the local endpoint.
+                </p>
+              </dd>
               <dt>
                 <dfn><code>targetBitrate</code></dfn> of type <span class=
                 "idlMemberType"><a>double</a></span>
@@ -1252,6 +1273,18 @@ <h2>
                   packetize the resulting data.
                 </p>
               </dd>
+              <dt>
+                <dfn><code>averageRTCPInterval</code></dfn> of type <span class=
+                "idlMemberType"><a>double</a></span>
+              </dt>
+              <dd>
+                <p>
+                  The average RTCP interval between two consecutive compound RTCP packets. This is
+                  calculated by the sending endpoint when sending compound RTCP reports. Compound
+                  packets must contain at least a RTCP RR or SR packet and an SDES packet with the
+                  CNAME item.
+                </p>
+              </dd>
             </dl>
           </section>
         </div>