Replace RTC_DEPRECATED with ABSL_DEPRECATED

This remove webrtc-specific macro that has no reason to be webrtc specific
ABSL_DEPRECATED takes a message parameter encouraging to write text how class or function is deprecated.

Bug: webrtc:12484
Change-Id: I89f1398f91dacadc37f7db469dcd985e3724e444
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/208282
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33314}
diff --git a/modules/video_coding/include/video_codec_interface.h b/modules/video_coding/include/video_codec_interface.h
index b786be1..4737dde 100644
--- a/modules/video_coding/include/video_codec_interface.h
+++ b/modules/video_coding/include/video_codec_interface.h
@@ -13,6 +13,7 @@
 
 #include <vector>
 
+#include "absl/base/attributes.h"
 #include "absl/types/optional.h"
 #include "api/video/video_frame.h"
 #include "api/video_codecs/video_decoder.h"
@@ -21,7 +22,6 @@
 #include "modules/video_coding/codecs/h264/include/h264_globals.h"
 #include "modules/video_coding/codecs/vp9/include/vp9_globals.h"
 #include "modules/video_coding/include/video_error_codes.h"
-#include "rtc_base/deprecation.h"
 #include "rtc_base/system/rtc_export.h"
 
 namespace webrtc {
@@ -79,7 +79,7 @@
   uint8_t num_ref_pics;
   uint8_t p_diff[kMaxVp9RefPics];
 
-  RTC_DEPRECATED bool end_of_picture;
+  ABSL_DEPRECATED("") bool end_of_picture;
 };
 static_assert(std::is_pod<CodecSpecificInfoVP9>::value, "");