RAPPOR metric for usage of RTCPeerConnection without connecting.

third_party/WebKit/Source/core/frame/HostsUsingFeatures.h

Index: third_party/WebKit/Source/core/frame/HostsUsingFeatures.h
diff --git a/third_party/WebKit/Source/core/frame/HostsUsingFeatures.h b/third_party/WebKit/Source/core/frame/HostsUsingFeatures.h
index 8087c78efe6945cb5a5b61414976c784542625eb..0415bdecb0ac7fbca9ff620c610419f18401e342 100644
--- a/third_party/WebKit/Source/core/frame/HostsUsingFeatures.h
+++ b/third_party/WebKit/Source/core/frame/HostsUsingFeatures.h
@@ -42,6 +42,7 @@ class CORE_EXPORT HostsUsingFeatures {
     RTCPeerConnectionAudio,
     RTCPeerConnectionVideo,
     RTCPeerConnectionDataChannel,
+    RTCPeerConnectionUsed,  // Note: Special treatment.

[Nate Chapin, 2017/01/27 20:38:59]

This comment doesn't really add anything. Please either describe the "Special
treatment" or remove the comment.

[hta - Chromium, 2017/01/29 03:12:38]

Changed to "Used to compute the "unconnected PCs" feature".
All the others are directly reported, I think, while this one is part of a
computation.

 
     NumberOfFeatures  // This must be the last item.
   };