Reland "Inform VideoEncoder of negotiated capabilities"

This is a reland of 11dfff0878c949f2e19d95a0ddc209cdad94b3b4

Now that I am sure that WebRTC code is not calling the obsolete
versions, I will just remove the NOT_REACHED and call the
new version from the old ones, so as not to trip up downstream
projects.

Original change's description:
> 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}

TBR=sakal@webrtc.org,kwiberg@webrtc.org,sprang@webrtc.org

Bug: webrtc:10720
Change-Id: I46c69e45c190805c07f7e51acbe277d7eebd1600
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/141412
Commit-Queue: Elad Alon <eladalon@webrtc.org>
Reviewed-by: Elad Alon <eladalon@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28236}
diff --git a/video/video_stream_encoder_unittest.cc b/video/video_stream_encoder_unittest.cc
index 1cf9436..1486606d 100644
--- a/video/video_stream_encoder_unittest.cc
+++ b/video/video_stream_encoder_unittest.cc
@@ -20,6 +20,7 @@
 #include "api/video/builtin_video_bitrate_allocator_factory.h"
 #include "api/video/i420_buffer.h"
 #include "api/video/video_bitrate_allocation.h"
+#include "api/video_codecs/video_encoder.h"
 #include "api/video_codecs/vp8_temporal_layers.h"
 #include "api/video_codecs/vp8_temporal_layers_factory.h"
 #include "common_video/h264/h264_common.h"
@@ -717,10 +718,8 @@
     }
 
     int32_t InitEncode(const VideoCodec* config,
-                       int32_t number_of_cores,
-                       size_t max_payload_size) override {
-      int res =
-          FakeEncoder::InitEncode(config, number_of_cores, max_payload_size);
+                       const Settings& settings) override {
+      int res = FakeEncoder::InitEncode(config, settings);
       rtc::CritScope lock(&local_crit_sect_);
       EXPECT_EQ(initialized_, EncoderState::kUninitialized);
       if (config->codecType == kVideoCodecVP8) {