Move usage of QualityScaler to ViEEncoder.

webrtc/modules/video_coding/codecs/vp8/simulcast_encoder_adapter.cc

Index: webrtc/modules/video_coding/codecs/vp8/simulcast_encoder_adapter.cc
diff --git a/webrtc/modules/video_coding/codecs/vp8/simulcast_encoder_adapter.cc b/webrtc/modules/video_coding/codecs/vp8/simulcast_encoder_adapter.cc
index 1c8037a60e9ce4657a146cd0ba888798e416ac40..7fa198b4a5f6bf8b584d325dcff4ec438a0dab9b 100644
--- a/webrtc/modules/video_coding/codecs/vp8/simulcast_encoder_adapter.cc
+++ b/webrtc/modules/video_coding/codecs/vp8/simulcast_encoder_adapter.cc
@@ -471,6 +471,15 @@ bool SimulcastEncoderAdapter::SupportsNativeHandle() const {
   return true;
 }
 
+QualityScaler::Settings SimulcastEncoderAdapter::GetQPThresholds() const {
+  // Turn off quality scaling for simulcast
+  RTC_DCHECK(!streaminfos_.empty()) << "Encoder must be initialized first.";
+  if (NumberOfStreams(codec_) > 1)
+    return QualityScaler::Settings(false);
+  else
+    return streaminfos_[0].encoder->GetQPThresholds();
+}
+
 const char* SimulcastEncoderAdapter::ImplementationName() const {
   return implementation_name_.c_str();
 }