Move usage of QualityScaler to ViEEncoder.

webrtc/video_encoder.h

Index: webrtc/video_encoder.h
diff --git a/webrtc/video_encoder.h b/webrtc/video_encoder.h
index 39a27a8bfcdb32707a10f759f00e244fc4227bc0..79f8a3d92d67eea30490efab9201068cfa6baeaf 100644
--- a/webrtc/video_encoder.h
+++ b/webrtc/video_encoder.h
@@ -18,6 +18,7 @@
 #include "webrtc/common_types.h"
 #include "webrtc/typedefs.h"
 #include "webrtc/video_frame.h"
+#include "webrtc/base/optional.h"
 
 namespace webrtc {
 
@@ -68,7 +69,20 @@ class VideoEncoder {
     kVp9,
     kUnsupportedCodec,
   };
-
+  struct QPThresholds {
+    QPThresholds(int l, int h) : low(l), high(h) {}
+    QPThresholds() : low(-1), high(-1) {}
+    int low;
+    int high;
+  };
+  struct ScalingSettings {
+    ScalingSettings(bool on, int low, int high)
+        : enabled(on),
+          thresholds(rtc::Optional<QPThresholds>(QPThresholds(low, high))) {}
+    explicit ScalingSettings(bool on) : enabled(on) {}
+    const bool enabled;
+    const rtc::Optional<QPThresholds> thresholds;
+  };
   static VideoEncoder* Create(EncoderType codec_type);
   // Returns true if this type of encoder can be created using
   // VideoEncoder::Create.
@@ -150,6 +164,12 @@ class VideoEncoder {
   // Return value                : WEBRTC_VIDEO_CODEC_OK if OK, < 0 otherwise.
   virtual int32_t SetRates(uint32_t bitrate, uint32_t framerate) = 0;
 
+  // Any encoder implementation wishing to use the WebRTC provided
+  // quality scaler must implement this method.
+  virtual ScalingSettings GetScalingSettings() const {
+    return ScalingSettings(false);
+  }
+
   virtual int32_t SetPeriodicKeyFrames(bool enable) { return -1; }
   virtual void OnDroppedFrame() {}
   virtual bool SupportsNativeHandle() const { return false; }