Remove warning on input frames before config.

Removes log spam for AppRTC when only one client is connected.

BUG=4512
R=stefan@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/48019005

Cr-Commit-Position: refs/heads/master@{#8947}

talk/media/webrtc/webrtcvideoengine2.cc

@@ -1491,8 +1491,7 @@ void WebRtcVideoChannel2::WebRtcVideoSendStream::InputFrame(
                                      frame->GetVideoRotation());
   rtc::CritScope cs(&lock_);
   if (stream_ == NULL) {
-    LOG(LS_WARNING) << "Capturer inputting frames before send codecs are "
-                       "configured, dropping.";
+    // Frame input before send codecs are configured, dropping frame.
     return;
   }