Remove QualityScaler framerate reduction.

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 5b2e94b88d53e85dd36c3b30da7c4b33a5c298a8..30a5776b2d05b6d92495e67dfb75743972809854 100644
--- a/webrtc/modules/video_coding/utility/quality_scaler.cc
+++ b/webrtc/modules/video_coding/utility/quality_scaler.cc
@@ -30,12 +30,10 @@ static const int kQvgaBitrateThresholdKbps = 250;
 static const int kQvgaNumPixels = 400 * 300;  // 320x240
 }  // namespace
 
-QualityScaler::QualityScaler()
-    : low_qp_threshold_(-1), framerate_down_(false) {}
+QualityScaler::QualityScaler() : low_qp_threshold_(-1) {}
 
 void QualityScaler::Init(int low_qp_threshold,
                          int high_qp_threshold,
-                         bool use_framerate_reduction,
                          int initial_bitrate_kbps,
                          int width,
                          int height,
@@ -43,7 +41,6 @@ void QualityScaler::Init(int low_qp_threshold,
   ClearSamples();
   low_qp_threshold_ = low_qp_threshold;
   high_qp_threshold_ = high_qp_threshold;
-  use_framerate_reduction_ = use_framerate_reduction;
   downscale_shift_ = 0;
   // Use a faster window for upscaling initially (but be more graceful later).
   // This enables faster initial rampups without risking strong up-down
@@ -65,7 +62,6 @@ void QualityScaler::Init(int low_qp_threshold,
   }
   UpdateTargetResolution(init_width, init_height);
   ReportFramerate(fps);
-  target_framerate_ = -1;
 }
 
 // Report framerate(fps) to estimate # of samples.
@@ -94,34 +90,14 @@ void QualityScaler::OnEncodeFrame(const VideoFrame& frame) {
   int avg_drop = 0;
   int avg_qp = 0;
 
-  // When encoder consistently overshoots, framerate reduction and spatial
-  // resizing will be triggered to get a smoother video.
   if ((framedrop_percent_.GetAverage(num_samples_downscale_, &avg_drop) &&
        avg_drop >= kFramedropPercentThreshold) ||
       (average_qp_downscale_.GetAverage(num_samples_downscale_, &avg_qp) &&
        avg_qp > high_qp_threshold_)) {
-    // Reducing frame rate before spatial resolution change.
-    // Reduce frame rate only when it is above a certain number.
-    // Only one reduction is allowed for now.
-    // TODO(jackychen): Allow more than one framerate reduction.
-    if (use_framerate_reduction_ && !framerate_down_ && framerate_ >= 20) {
-      target_framerate_ = framerate_ / 2;
-      framerate_down_ = true;
-      // If frame rate has been updated, clear the buffer. We don't want
-      // spatial resolution to change right after frame rate change.
-      ClearSamples();
-    } else {
-      AdjustScale(false);
-    }
+    AdjustScale(false);
   } else if (average_qp_upscale_.GetAverage(num_samples_upscale_, &avg_qp) &&
              avg_qp <= low_qp_threshold_) {
-    if (use_framerate_reduction_ && framerate_down_) {
-      target_framerate_ = -1;
-      framerate_down_ = false;
-      ClearSamples();
-    } else {
-      AdjustScale(true);
-    }
+    AdjustScale(true);
   }
   UpdateTargetResolution(frame.width(), frame.height());
 }
@@ -130,10 +106,6 @@ QualityScaler::Resolution QualityScaler::GetScaledResolution() const {
   return res_;
 }
 
-int QualityScaler::GetTargetFramerate() const {
-  return target_framerate_;
-}
-
 const VideoFrame& QualityScaler::GetScaledFrame(const VideoFrame& frame) {
   Resolution res = GetScaledResolution();
   if (res.width == frame.width())