Use initial bitrates for software VP8.

webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc

Index: webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc
diff --git a/webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc b/webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc
index abe58e362699534047322cc096554613f7f46acc..88ca85feade3626b1915ca4aeb4ded44be7b0f51 100644
--- a/webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc
+++ b/webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc
@@ -606,9 +606,8 @@ int VP8EncoderImpl::InitEncode(const VideoCodec* inst,
   // go back down).
   const int kLowQpThreshold = 29;
   const int kDisabledBadQpThreshold = 100;
-  // TODO(glaznev/sprang): consider passing codec initial bitrate to quality
-  // scaler to avoid starting with HD for low initial bitrates.
-  quality_scaler_.Init(kLowQpThreshold, kDisabledBadQpThreshold, false, 0, 0, 0,
+  quality_scaler_.Init(kLowQpThreshold, kDisabledBadQpThreshold, false,
+                       codec_.startBitrate, codec_.width, codec_.height,
                        codec_.maxFramerate);
 
   // Only apply scaling to improve for single-layer streams. The scaling metrics