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

webrtc/modules/video_coding/codecs/h264/h264_encoder_impl.cc

Index: webrtc/modules/video_coding/codecs/h264/h264_encoder_impl.cc
diff --git a/webrtc/modules/video_coding/codecs/h264/h264_encoder_impl.cc b/webrtc/modules/video_coding/codecs/h264/h264_encoder_impl.cc
index 2070f22890ff90d3028f91ab034ae342c7014bce..2ea76fdc6c4b96b093e835c5845dcfa9b435c492 100644
--- a/webrtc/modules/video_coding/codecs/h264/h264_encoder_impl.cc
+++ b/webrtc/modules/video_coding/codecs/h264/h264_encoder_impl.cc
@@ -252,11 +252,13 @@ int32_t H264EncoderImpl::RegisterEncodeCompleteCallback(
   return WEBRTC_VIDEO_CODEC_OK;
 }
 
-int32_t H264EncoderImpl::SetRates(uint32_t bitrate, uint32_t framerate) {
-  if (bitrate <= 0 || framerate <= 0) {
+int32_t H264EncoderImpl::SetRateAllocation(
+    const BitrateAllocation& bitrate_allocation,
+    uint32_t framerate) {
+  if (bitrate_allocation.get_sum_kbps() <= 0 || framerate <= 0) {
     return WEBRTC_VIDEO_CODEC_ERR_PARAMETER;
   }
-  codec_settings_.targetBitrate = bitrate;
+  codec_settings_.targetBitrate = bitrate_allocation.get_sum_kbps();
   codec_settings_.maxFramerate = framerate;
   quality_scaler_.ReportFramerate(framerate);