Revert of Issue 2434073003: Extract bitrate allocation ... (patchset #4 id:60001 of https://codereview.webrtc.org/2488833004/ )

Reason for revert:
Seems to be causing flakiness in perf test:
FullStackTest.ScreenshareSlidesVP8_2TL_LossyNet

Original issue's description:
> Reland of Issue 2434073003: Extract bitrate allocation ...
>
> This is a reland of https://codereview.webrtc.org/2434073003/ including
> some fixes for failing test cases.
>
> Original description:
>
> Extract bitrate allocation of spatial/temporal layers out of codec impl.
>
> This CL makes a number of intervowen changes:
>
> * Add BitrateAllocation struct, that contains a codec independent view
>   of how the target bitrate is distributed over spatial and temporal
>   layers.
>
> * Adds the BitrateAllocator interface, which takes a bitrate and frame
>   rate and produces a BitrateAllocation.
>
> * A default (non layered) implementation is added, and
>   SimulcastRateAllocator is extended to fully handle VP8 allocation.
>   This includes capturing TemporalLayer instances created by the
>   encoder.
>
> * ViEEncoder now owns both the bitrate allocator and the temporal layer
>   factories for VP8. This allows allocation to happen fully outside of
>   the encoder implementation.
>
> This refactoring will make it possible for ViEEncoder to signal the
> full picture of target bitrates to the RTCP module.
>
> BUG=webrtc:6301
>
> Committed: https://crrev.com/647bf43dcb2fd16fccf276bd94dc4400728bb405
> Cr-Commit-Position: refs/heads/master@{#15023}

TBR=mflodman@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:6301

Review-Url: https://codereview.webrtc.org/2491393002
Cr-Commit-Position: refs/heads/master@{#15026}
diff --git a/webrtc/modules/video_coding/video_coding_impl.cc b/webrtc/modules/video_coding/video_coding_impl.cc
index 021281b..2f709b6 100644
--- a/webrtc/modules/video_coding/video_coding_impl.cc
+++ b/webrtc/modules/video_coding/video_coding_impl.cc
@@ -11,14 +11,10 @@
 #include "webrtc/modules/video_coding/video_coding_impl.h"
 
 #include <algorithm>
-#include <utility>
 
 #include "webrtc/common_types.h"
-#include "webrtc/common_video/include/video_bitrate_allocator.h"
 #include "webrtc/common_video/libyuv/include/webrtc_libyuv.h"
 #include "webrtc/base/criticalsection.h"
-#include "webrtc/modules/video_coding/codecs/vp8/temporal_layers.h"
-#include "webrtc/modules/video_coding/include/video_codec_initializer.h"
 #include "webrtc/modules/video_coding/include/video_codec_interface.h"
 #include "webrtc/modules/video_coding/encoded_frame.h"
 #include "webrtc/modules/video_coding/jitter_buffer.h"
@@ -108,21 +104,6 @@
   int32_t RegisterSendCodec(const VideoCodec* sendCodec,
                             uint32_t numberOfCores,
                             uint32_t maxPayloadSize) override {
-    if (sendCodec != nullptr && sendCodec->codecType == kVideoCodecVP8) {
-      // Set up a rate allocator and temporal layers factory for this vp8
-      // instance. The codec impl will have a raw pointer to the TL factory,
-      // and will call it when initializing. Since this can happen
-      // asynchronously keep the instance alive until destruction or until a
-      // new send codec is registered.
-      VideoCodec vp8_codec = *sendCodec;
-      std::unique_ptr<TemporalLayersFactory> tl_factory(
-          new TemporalLayersFactory());
-      vp8_codec.VP8()->tl_factory = tl_factory.get();
-      rate_allocator_ = VideoCodecInitializer::CreateBitrateAllocator(
-          vp8_codec, std::move(tl_factory));
-      return sender_.RegisterSendCodec(&vp8_codec, numberOfCores,
-                                       maxPayloadSize);
-    }
     return sender_.RegisterSendCodec(sendCodec, numberOfCores, maxPayloadSize);
   }
 
@@ -145,8 +126,7 @@
   int32_t SetChannelParameters(uint32_t target_bitrate,  // bits/s.
                                uint8_t lossRate,
                                int64_t rtt) override {
-    return sender_.SetChannelParameters(target_bitrate, lossRate, rtt,
-                                        rate_allocator_.get());
+    return sender_.SetChannelParameters(target_bitrate, lossRate, rtt);
   }
 
   int32_t RegisterProtectionCallback(
@@ -276,7 +256,6 @@
  private:
   EncodedImageCallbackWrapper post_encode_callback_;
   vcm::VideoSender sender_;
-  std::unique_ptr<VideoBitrateAllocator> rate_allocator_;
   vcm::VideoReceiver receiver_;
 };
 }  // namespace