Inform VideoEncoder of negotiated capabilities

After this CL lands, an announcement will be made to
discuss-webrtc about the deprecation of one version
of InitEncode().

Bug: webrtc:10720
Change-Id: Ib992af0272bbb16ae16ef7e69491f365702d179e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/140884
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Elad Alon <eladalon@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28224}

modules/video_coding/codecs/h264/h264_encoder_impl.h

@@ -25,6 +25,7 @@
 #include <vector>
 
 #include "api/video/i420_buffer.h"
+#include "api/video_codecs/video_encoder.h"
 #include "common_video/h264/h264_bitstream_parser.h"
 #include "modules/video_coding/codecs/h264/include/h264.h"
 #include "modules/video_coding/utility/quality_scaler.h"
@@ -66,6 +67,8 @@ class H264EncoderImpl : public H264Encoder {
   int32_t InitEncode(const VideoCodec* codec_settings,
                      int32_t number_of_cores,
                      size_t max_payload_size) override;
+  int32_t InitEncode(const VideoCodec* codec_settings,
+                     const VideoEncoder::Settings& settings) override;
   int32_t Release() override;
 
   int32_t RegisterEncodeCompleteCallback(