Recreate WebrtcVideoSendStream if screen content setting is changed.

webrtc/media/engine/webrtcvideoengine2.cc

Index: webrtc/media/engine/webrtcvideoengine2.cc
diff --git a/webrtc/media/engine/webrtcvideoengine2.cc b/webrtc/media/engine/webrtcvideoengine2.cc
index c192b52402ee95ef3f2ffd9dbe25f65ded5ecf6d..8c6bd848fc18076539cee73cece1655e3629e073 100644
--- a/webrtc/media/engine/webrtcvideoengine2.cc
+++ b/webrtc/media/engine/webrtcvideoengine2.cc
@@ -1612,7 +1612,12 @@ bool WebRtcVideoChannel2::WebRtcVideoSendStream::SetVideoSend(
   if (options_present) {
     VideoOptions old_options = parameters_.options;
     parameters_.options.SetAll(*options);
-    if (parameters_.options != old_options) {
+    if (parameters_.options.is_screencast.value_or(false) !=
+        old_options.is_screencast.value_or(false)) {
+      // If screen content settings change, we may need to recreate the
+      // stream so that the correct encoder is created.

[pthatcher1, 2017/02/21 23:00:34]

This could use a little more detail about why it's necessary.

+      RecreateWebRtcStream();
+    } else {

[pthatcher1, 2017/02/21 23:00:34]

Shouldn't this be "else if (parameters_.options != old_options)" ?  Otherwise,
we'd reconfigure even if the options didn't change.

[Taylor Brandstetter, 2017/02/22 00:27:24]

+1

[sprang_webrtc, 2017/02/22 15:53:04]

Yes, I screwed up copy/paste from a chromium checkout where I was iterating and
testing...

       ReconfigureEncoder();
     }
   }