Extract bitrate allocation of spatial/temporal layers out of codec impl.

webrtc/video_encoder.h

Index: webrtc/video_encoder.h
diff --git a/webrtc/video_encoder.h b/webrtc/video_encoder.h
index d28533b9fd062f23c12cf1ff10f984b501f90259..bbe69b78dd9d238e3bec733a0dec979759ef0e42 100644
--- a/webrtc/video_encoder.h
+++ b/webrtc/video_encoder.h
@@ -15,6 +15,7 @@
 #include <string>
 #include <vector>
 
+#include "webrtc/base/checks.h"
 #include "webrtc/common_types.h"
 #include "webrtc/typedefs.h"
 #include "webrtc/video_frame.h"
@@ -161,7 +162,17 @@ class VideoEncoder {
   //          - framerate       : The target frame rate
   //
   // Return value                : WEBRTC_VIDEO_CODEC_OK if OK, < 0 otherwise.
-  virtual int32_t SetRates(uint32_t bitrate, uint32_t framerate) = 0;
+  virtual int32_t SetRates(uint32_t bitrate, uint32_t framerate) {
+    RTC_NOTREACHED() << "SetRate(uint32_t, uint32_t) is deprecated.";
+    return -1;
+  }
+
+  // Default fallback: Just use the sum of bitrates as the single target rate.
+  // TODO(sprang): Remove this default implementation when we remove SetRates().
+  virtual int32_t SetRateAllocation(const BitrateAllocation& allocation,
+                                    uint32_t framerate) {
+    return SetRates(allocation.get_sum_kbps(), framerate);
+  }
 
   virtual int32_t SetPeriodicKeyFrames(bool enable) { return -1; }
   virtual void OnDroppedFrame() {}
@@ -189,8 +200,8 @@ class VideoEncoderSoftwareFallbackWrapper : public VideoEncoder {
                  const CodecSpecificInfo* codec_specific_info,
                  const std::vector<FrameType>* frame_types) override;
   int32_t SetChannelParameters(uint32_t packet_loss, int64_t rtt) override;
-
-  int32_t SetRates(uint32_t bitrate, uint32_t framerate) override;
+  int32_t SetRateAllocation(const BitrateAllocation& bitrate_allocation,
+                            uint32_t framerate) override;
   void OnDroppedFrame() override;
   bool SupportsNativeHandle() const override;
 
@@ -205,7 +216,7 @@ class VideoEncoderSoftwareFallbackWrapper : public VideoEncoder {
 
   // The last bitrate/framerate set, and a flag for noting they are set.
   bool rates_set_;
-  uint32_t bitrate_;
+  BitrateAllocation bitrate_;
   uint32_t framerate_;
 
   // The last channel parameters set, and a flag for noting they are set.