Reland of Delete deprecated and transitional stuff related to video frame refactoring. (patchset #1 id:1 of https://codereview.webrtc.org/2845333002/ )

Reason for revert:
Downstream projects being updated.

For Chrome, relanding depends on cl
https://codereview.chromium.org/2855783003/

Original issue's description:
> Revert of Delete deprecated and transitional stuff related to video frame refactoring. (patchset #17 id:320001 of https://codereview.webrtc.org/2622263002/ )
>
> Reason for revert:
> Broke Chrome build, see, e.g.,
> http://build.chromium.org/p/chromium.webrtc.fyi/builders/Linux%20Builder/builds/16237
>
> Original issue's description:
> > Delete deprecated and transitional stuff related to video frame refactoring.
> >
> > BUG=webrtc:5880
> >
> > Review-Url: https://codereview.webrtc.org/2622263002
> > Cr-Commit-Position: refs/heads/master@{#17928}
> > Committed: 713a3bbcc7
>
> TBR=mflodman@webrtc.org,perkj@webrtc.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=webrtc:5880
>
> Review-Url: https://codereview.webrtc.org/2845333002
> Cr-Commit-Position: refs/heads/master@{#17929}
> Committed: aec49d2b49

TBR=mflodman@webrtc.org,perkj@webrtc.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=webrtc:5880

Review-Url: https://codereview.webrtc.org/2852303002
Cr-Commit-Position: refs/heads/master@{#17974}

webrtc/api/video_codecs/BUILD.gn

@@ -22,6 +22,7 @@ rtc_source_set("video_codecs_api") {
     # TODO(ilnik): Add dependency on webrtc/video_frame.h when it will have it's
     # own build target.
 
+    "..:video_frame_api",
     "../..:webrtc_common",
     "../../base:rtc_base_approved",
   ]

webrtc/api/video_codecs/video_decoder.h

@@ -15,6 +15,7 @@
 #include <string>
 #include <vector>
 
+#include "webrtc/api/video/video_frame.h"
 #include "webrtc/common_types.h"
 #include "webrtc/typedefs.h"
 #include "webrtc/video_frame.h"

webrtc/api/video_codecs/video_encoder.h

@@ -15,6 +15,7 @@
 #include <string>
 #include <vector>
 
+#include "webrtc/api/video/video_frame.h"
 #include "webrtc/base/checks.h"
 #include "webrtc/common_types.h"
 #include "webrtc/typedefs.h"