Move the QP scaling thresholds to the relevant encoders

webrtc/modules/video_coding/utility/quality_scaler.cc

Index: webrtc/modules/video_coding/utility/quality_scaler.cc
diff --git a/webrtc/modules/video_coding/utility/quality_scaler.cc b/webrtc/modules/video_coding/utility/quality_scaler.cc
index c509e843642f2237e94fe1727749479a9523faa7..f46ddba0ab8daa7b2a1f3e12ea88364b41cf7026 100644
--- a/webrtc/modules/video_coding/utility/quality_scaler.cc
+++ b/webrtc/modules/video_coding/utility/quality_scaler.cc
@@ -31,21 +31,6 @@ static const int kQvgaBitrateThresholdKbps = 250;
 static const int kQvgaNumPixels = 400 * 300;  // 320x240
 }  // namespace
 
-// QP thresholds are chosen to be high enough to be hit in practice when quality
-// is good, but also low enough to not cause a flip-flop behavior (e.g. going up
-// in resolution shouldn't give so bad quality that we should go back down).
-
-const int QualityScaler::kLowVp8QpThreshold = 29;
-const int QualityScaler::kBadVp8QpThreshold = 95;
-
-#if defined(WEBRTC_IOS)
-const int QualityScaler::kLowH264QpThreshold = 32;
-const int QualityScaler::kBadH264QpThreshold = 42;
-#else
-const int QualityScaler::kLowH264QpThreshold = 24;
-const int QualityScaler::kBadH264QpThreshold = 37;
-#endif
-
 QualityScaler::QualityScaler() : low_qp_threshold_(-1) {}
 
 void QualityScaler::Init(int low_qp_threshold,