Revert of Enable H.264 video WebRTC behind run-time flag and add WebRtcBrowserTest for H.264

content/public/common/feature_h264_with_openh264_ffmpeg.h

Index: content/public/common/feature_h264_with_openh264_ffmpeg.h
diff --git a/content/public/common/feature_h264_with_openh264_ffmpeg.h b/content/public/common/feature_h264_with_openh264_ffmpeg.h
deleted file mode 100644
index 93961fceebb71335d3c9f76ca73a769ffe3ac052..0000000000000000000000000000000000000000
--- a/content/public/common/feature_h264_with_openh264_ffmpeg.h
+++ /dev/null
@@ -1,22 +0,0 @@
-// Copyright 2013 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CONTENT_PUBLIC_COMMON_FEATURE_H264_WITH_OPENH264_FFMPEG_H_
-#define CONTENT_PUBLIC_COMMON_FEATURE_H264_WITH_OPENH264_FFMPEG_H_
-
-#include "base/feature_list.h"
-#include "content/public/common/common_features.h"
-
-namespace content {
-
-#if BUILDFLAG(RTC_USE_H264)
-
-// Run-time feature for the |rtc_use_h264| encoder/decoder.
-extern const base::Feature kWebRtcH264WithOpenH264FFmpeg;
-
-#endif  // BUILDFLAG(RTC_USE_H264)
-
-} // namespace content
-
-#endif  // CONTENT_PUBLIC_COMMON_FEATURE_H264_WITH_OPENH264_FFMPEG_H_