Migrate WebRTC on FrameGeneratorInterface and remove FrameGenerator class

Bug: webrtc:10138
Change-Id: If85290581a72f81cf60181de7a7134cc9db7716e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/161327
Reviewed-by: Niels Moller <nisse@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30033}
diff --git a/modules/video_coding/BUILD.gn b/modules/video_coding/BUILD.gn
index ceee019..be610e7 100644
--- a/modules/video_coding/BUILD.gn
+++ b/modules/video_coding/BUILD.gn
@@ -614,6 +614,8 @@
       ":videocodec_test_stats_impl",
       ":webrtc_vp9_helpers",
       "..:module_api",
+      "../../api:create_frame_generator",
+      "../../api:frame_generator_api",
       "../../api:scoped_refptr",
       "../../api:videocodec_test_fixture_api",
       "../../api/task_queue",
@@ -759,7 +761,9 @@
       ":webrtc_vp9",
       ":webrtc_vp9_helpers",
       "../..:webrtc_common",
+      "../../api:create_frame_generator",
       "../../api:create_videocodec_test_fixture_api",
+      "../../api:frame_generator_api",
       "../../api:mock_video_codec_factory",
       "../../api:mock_video_decoder",
       "../../api:mock_video_encoder",