Revert "Use the factory instead of using the builtin code path in `VideoCodecInitializer`."

This reverts commit be142178aaf6ab4089b4d81c88c3d59c12cca567.

Reason for revert: breaking internal projects

Original change's description:
> Use the factory instead of using the builtin code path in `VideoCodecInitializer`.
> 
> Bug: webrtc:9513
> Change-Id: Ia299ae1044a3ff4c91e208200938cba540bdcea6
> Reviewed-on: https://webrtc-review.googlesource.com/c/94782
> Commit-Queue: Jiawei Ou <ouj@fb.com>
> Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
> Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
> Reviewed-by: Sebastian Jansson <srte@webrtc.org>
> Reviewed-by: Anders Carlsson <andersc@webrtc.org>
> Reviewed-by: Seth Hampson <shampson@webrtc.org>
> Reviewed-by: Erik Språng <sprang@webrtc.org>
> Reviewed-by: Niels Moller <nisse@webrtc.org>
> Reviewed-by: Rasmus Brandt <brandtr@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#25456}

TBR=brandtr@webrtc.org,magjed@webrtc.org,sakal@webrtc.org,nisse@webrtc.org,andersc@webrtc.org,tommi@webrtc.org,kthelgason@webrtc.org,sprang@webrtc.org,srte@webrtc.org,perkj@webrtc.org,tkchin@webrtc.org,shampson@webrtc.org,glaznev@webrtc.org,ouj@fb.com,qingsi@webrtc.org

Change-Id: I8040ccabe3ae6464d72c7696adb663c1dd275b63
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:9513
Reviewed-on: https://webrtc-review.googlesource.com/c/108980
Reviewed-by: Qingsi Wang <qingsi@webrtc.org>
Commit-Queue: Qingsi Wang <qingsi@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25459}
diff --git a/modules/video_coding/video_coding_impl.cc b/modules/video_coding/video_coding_impl.cc
index 1460f6a..a061c18 100644
--- a/modules/video_coding/video_coding_impl.cc
+++ b/modules/video_coding/video_coding_impl.cc
@@ -13,7 +13,6 @@
 #include <algorithm>
 #include <utility>
 
-#include "api/video/builtin_video_bitrate_allocator_factory.h"
 #include "api/video/video_bitrate_allocator.h"
 #include "common_types.h"  // NOLINT(build/include)
 #include "common_video/libyuv/include/webrtc_libyuv.h"
@@ -87,7 +86,6 @@
                         KeyFrameRequestSender* keyframe_request_sender)
       : VideoCodingModule(),
         sender_(clock, &post_encode_callback_),
-        rate_allocator_factory_(CreateBuiltinVideoBitrateAllocatorFactory()),
         timing_(new VCMTiming(clock)),
         receiver_(clock,
                   event_factory,
@@ -116,8 +114,7 @@
       // asynchronously keep the instance alive until destruction or until a
       // new send codec is registered.
       VideoCodec codec = *sendCodec;
-      rate_allocator_ =
-          rate_allocator_factory_->CreateVideoBitrateAllocator(codec);
+      rate_allocator_ = VideoCodecInitializer::CreateBitrateAllocator(codec);
       return sender_.RegisterSendCodec(&codec, numberOfCores, maxPayloadSize);
     }
     return sender_.RegisterSendCodec(sendCodec, numberOfCores, maxPayloadSize);
@@ -216,9 +213,8 @@
   rtc::ThreadChecker construction_thread_;
   EncodedImageCallbackWrapper post_encode_callback_;
   vcm::VideoSender sender_;
-  const std::unique_ptr<VideoBitrateAllocatorFactory> rate_allocator_factory_;
   std::unique_ptr<VideoBitrateAllocator> rate_allocator_;
-  const std::unique_ptr<VCMTiming> timing_;
+  std::unique_ptr<VCMTiming> timing_;
   vcm::VideoReceiver receiver_;
 };
 }  // namespace