Move VideoStreamEncoderInterface to api/.

Bug: webrtc:8830
Change-Id: I17908b4ef6a043acf22e2110b9672012d5fa7fc0
Reviewed-on: https://webrtc-review.googlesource.com/74481
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Rasmus Brandt <brandtr@webrtc.org>
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23334}
diff --git a/media/base/mediachannel.h b/media/base/mediachannel.h
index e5a6df2..2580c0d 100644
--- a/media/base/mediachannel.h
+++ b/media/base/mediachannel.h
@@ -24,9 +24,10 @@
 #include "api/rtpparameters.h"
 #include "api/rtpreceiverinterface.h"
 #include "api/video/video_content_type.h"
-#include "api/video/video_timing.h"
 #include "api/video/video_sink_interface.h"
-#include "api/videosourceinterface.h"
+#include "api/video/video_source_interface.h"
+#include "api/video/video_timing.h"
+#include "api/video_codecs/video_encoder_config.h"
 #include "media/base/codec.h"
 #include "media/base/mediaconfig.h"
 #include "media/base/mediaconstants.h"
@@ -42,7 +43,6 @@
 #include "rtc_base/socket.h"
 #include "rtc_base/stringencode.h"
 
-
 namespace rtc {
 class Timing;
 }