New file api/video/BUILD.gn

Build targets involving files under api/video/ are moved into this
file, from api/BUILD.gn. In addition, drop "_api" part of target
names, and move the header file api/videosinkinterface.h to
api/video/video_sink_interface.h.

Bug: webrtc:9253
Change-Id: I2896d3f063db8dff902bc29738578395b2fcc155
Reviewed-on: https://webrtc-review.googlesource.com/75500
Commit-Queue: Niels Moller <nisse@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23207}
diff --git a/examples/BUILD.gn b/examples/BUILD.gn
index ed6e060..90b8679 100644
--- a/examples/BUILD.gn
+++ b/examples/BUILD.gn
@@ -632,7 +632,7 @@
     }
     deps = [
       "../api:libjingle_peerconnection_api",
-      "../api:video_frame_api_i420",
+      "../api/video:video_frame_i420",
       "../rtc_base:checks",
       "../rtc_base:stringutils",
     ]
@@ -667,9 +667,9 @@
     deps += [
       "../api:libjingle_peerconnection_api",
       "../api:libjingle_peerconnection_test_api",
-      "../api:video_frame_api",
       "../api/audio_codecs:builtin_audio_decoder_factory",
       "../api/audio_codecs:builtin_audio_encoder_factory",
+      "../api/video:video_frame",
       "../api/video_codecs:builtin_video_decoder_factory",
       "../api/video_codecs:builtin_video_encoder_factory",
       "../media:rtc_audio_video",
@@ -803,9 +803,9 @@
     deps = [
       "../api:libjingle_peerconnection_api",
       "../api:libjingle_peerconnection_test_api",
-      "../api:video_frame_api",
       "../api/audio_codecs:builtin_audio_decoder_factory",
       "../api/audio_codecs:builtin_audio_encoder_factory",
+      "../api/video:video_frame",
       "../media:rtc_audio_video",
       "../media:rtc_internal_video_codecs",
       "../media:rtc_media",