Revert of Delete deprecated and transitional stuff related to video frame refactoring.

webrtc/media/base/videocapturer.h

Index: webrtc/media/base/videocapturer.h
diff --git a/webrtc/media/base/videocapturer.h b/webrtc/media/base/videocapturer.h
index 76ab95a2b8ee99989675a3941acdf2a96ab160a0..510063bc16bc9c4842938ac98533b2020df678d0 100644
--- a/webrtc/media/base/videocapturer.h
+++ b/webrtc/media/base/videocapturer.h
@@ -19,6 +19,12 @@
 #include <memory>
 #include <string>
 #include <vector>
+
+// TODO(nisse): Transition hack, some downstream applications expect that
+// including this file declares I420Buffer and NativeHandleBuffer. Delete after
+// users of these classes are fixed to include the right headers.
+#include "webrtc/api/video/i420_buffer.h"
+#include "webrtc/common_video/include/video_frame_buffer.h"
 
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/base/criticalsection.h"