RTCPeerConnection.getStats gets LegacyInterfaceTypeChecking.

third_party/WebKit/LayoutTests/fast/peerconnection/RTCPeerConnection-stats.html

Index: third_party/WebKit/LayoutTests/fast/peerconnection/RTCPeerConnection-stats.html
diff --git a/third_party/WebKit/LayoutTests/fast/peerconnection/RTCPeerConnection-stats.html b/third_party/WebKit/LayoutTests/fast/peerconnection/RTCPeerConnection-stats.html
index d7ec572bf54046b5cf1d8fede9231e5cc1a07283..31b3349be00ced3a50663939a2ac4266d285db52 100644
--- a/third_party/WebKit/LayoutTests/fast/peerconnection/RTCPeerConnection-stats.html
+++ b/third_party/WebKit/LayoutTests/fast/peerconnection/RTCPeerConnection-stats.html
@@ -78,6 +78,13 @@ function statsHandler3(status)
 {
     testPassed("statsHandler3 was called");
     verifyStats(status);
+    // Silly non-MediaStreamTrack second argument should be interpreted as undefined.
+    shouldNotThrow('pc.getStats(statsHandler4, 42)');
+}
+
+function statsHandler4(status) {
+    testPassed("statsHandler4 was called");
+    verifyStats(status);
     finishJSTest();
 }