webrtc-internals: detect SDP munging

show in the webrtc-internals page that you are using SDP munging
BUG=823036

Change-Id: I874bc4575f7718355336507d84c7616971c30e6b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1953635
Commit-Queue: Philipp Hancke <philipp.hancke@googlemail.com>
Reviewed-by: Harald Alvestrand <hta@chromium.org>
Reviewed-by: Henrik Boström <hbos@chromium.org>
Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Cr-Commit-Position: refs/heads/master@{#737247}

content/browser/resources/media/peer_connection_update_table.js

@@ -109,6 +109,14 @@ var PeerConnectionUpdateTable = (function() {
         if (candidateType) {
           type += ' (' + candidateType[1] + ')';
         }
+      } else if (
+          update.type === 'createOfferOnSuccess' ||
+          update.type === 'createAnswerOnSuccess') {
+        this.setLastOfferAnswer_(tableElement, update);
+      } else if (update.type === 'setLocalDescription') {
+        if (update.value !== this.getLastOfferAnswer_(tableElement)) {
+          type += ' (munged)';
+        }
       }
       row.innerHTML +=
           '<td><details><summary>' + type + '</summary></details></td>';
@@ -186,6 +194,29 @@ var PeerConnectionUpdateTable = (function() {
             '<th class="update-log-header-event">Event</th></tr>';
       }
       return tableElement;
+    },
+
+    /**
+     * Store the last createOfferOnSuccess/createAnswerOnSuccess to compare to
+     * setLocalDescription and visualize SDP munging.
+     *
+     * @param {!Element} tableElement The peerconnection update element.
+     * @param {!PeerConnectionUpdateEntry} update The update to add.
+     * @private
+     */
+    setLastOfferAnswer_: function(tableElement, update) {
+      tableElement['data-lastofferanswer'] = update.value;
+    },
+
+    /**
+     * Retrieves the last createOfferOnSuccess/createAnswerOnSuccess to compare
+     * to setLocalDescription and visualize SDP munging.
+     *
+     * @param {!Element} tableElement The peerconnection update element.
+     * @private
+     */
+    getLastOfferAnswer_: function(tableElement) {
+      return tableElement['data-lastofferanswer'];
     }
   };
 

content/browser/webrtc/webrtc_internals_browsertest.cc

@@ -564,6 +564,8 @@ IN_PROC_BROWSER_TEST_F(MAYBE_WebRtcInternalsBrowserTest, UpdatePeerConnection) {
   ExecuteAndVerifyUpdatePeerConnection(pc_2, "setRemoteDescription",
       ssrc1.GetSsrcAttributeString());
 
+  ExecuteAndVerifyUpdatePeerConnection(pc_2, "createAnswerOnSuccess",
+                                       ssrc2.GetSsrcAttributeString());
   ExecuteAndVerifyUpdatePeerConnection(pc_2, "setLocalDescription",
       ssrc2.GetSsrcAttributeString());