Revert of Add content type information to encoded images and corresponding rtp extension header

webrtc/modules/rtp_rtcp/source/rtp_header_extensions.cc

Index: webrtc/modules/rtp_rtcp/source/rtp_header_extensions.cc
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.cc b/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.cc
index 8141f0229011b2cb4fb34fbebb38a3e53c7f82fd..1b311e64190cd80eb146ddba3628ac67a503d30d 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.cc
+++ b/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.cc
@@ -215,33 +215,4 @@
   return true;
 }
 
-// Video Content Type.
-//
-// E.g. default video or screenshare.
-//
-//    0                   1
-//    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
-//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-//   |  ID   | len=0 | Content type  |
-//   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-constexpr RTPExtensionType VideoContentTypeExtension::kId;
-constexpr uint8_t VideoContentTypeExtension::kValueSizeBytes;
-constexpr const char* VideoContentTypeExtension::kUri;
-
-bool VideoContentTypeExtension::Parse(rtc::ArrayView<const uint8_t> data,
-                                      VideoContentType* content_type) {
-  if (data.size() == 1 &&
-      data[0] < static_cast<uint8_t>(VideoContentType::TOTAL_CONTENT_TYPES)) {
-    *content_type = static_cast<VideoContentType>(data[0]);
-    return true;
-  }
-  return false;
-}
-
-bool VideoContentTypeExtension::Write(uint8_t* data,
-                                      VideoContentType content_type) {
-  data[0] = static_cast<uint8_t>(content_type);
-  return true;
-}
-
 }  // namespace webrtc