Implement googContentType GetStats metric reported on receive side.

webrtc/video/receive_statistics_proxy.cc

Index: webrtc/video/receive_statistics_proxy.cc
diff --git a/webrtc/video/receive_statistics_proxy.cc b/webrtc/video/receive_statistics_proxy.cc
index 6e58e1e86b6418892ab80999227582b0dbd5f89b..ba1244744652a51bc54a40a77ad4b61ce53ce221 100644
--- a/webrtc/video/receive_statistics_proxy.cc
+++ b/webrtc/video/receive_statistics_proxy.cc
@@ -499,6 +499,11 @@ VideoReceiveStream::Stats ReceiveStatisticsProxy::GetStats() const {
       static_cast<int>(total_byte_tracker_.ComputeRate() * 8);
   stats_.interframe_delay_max_ms =
       interframe_delay_max_moving_.Max(now_ms).value_or(-1);
+  if (videocontenttypehelpers::IsScreenshare(last_content_type_)) {
+    stats_.content_type = "screen";
+  } else {
+    stats_.content_type = "realtime";

[tommi, 2017/08/30 15:03:28]

fyi - the code generation for this statement generates code for two calls to the
assignment operator. An alternative could be:

stats_.content_type = videocontenttypehelpers::IsScreenshare(last_content_type_)
: "screen" : "realtime";

[ilnik, 2017/08/30 15:30:24]

Done.

+  }
   return stats_;
 }