media: Use IPC_STRUCT_TRAITS to convert SubsampleEntry for mojo

media/mojo/common/media_type_converters.h

Index: media/mojo/common/media_type_converters.h
diff --git a/media/mojo/common/media_type_converters.h b/media/mojo/common/media_type_converters.h
index 0fea86a84841c24c54c0f1bcecd144521117e293..d0afe7060aba25957eceec67080fbdf1060cb4a3 100644
--- a/media/mojo/common/media_type_converters.h
+++ b/media/mojo/common/media_type_converters.h
@@ -22,7 +22,6 @@ class VideoDecoderConfig;
 class VideoFrame;
 struct CdmConfig;
 struct CdmKeyInformation;
-struct SubsampleEntry;
 }
 
 // These are specializations of mojo::TypeConverter and have to be in the mojo
@@ -43,17 +42,6 @@ struct TypeConverter<media::EncryptionScheme,
 };
 
 template <>
-struct TypeConverter<media::mojom::SubsampleEntryPtr, media::SubsampleEntry> {
-  static media::mojom::SubsampleEntryPtr Convert(
-      const media::SubsampleEntry& input);
-};
-template <>
-struct TypeConverter<media::SubsampleEntry, media::mojom::SubsampleEntryPtr> {
-  static media::SubsampleEntry Convert(
-      const media::mojom::SubsampleEntryPtr& input);
-};
-
-template <>
 struct TypeConverter<media::mojom::DecryptConfigPtr, media::DecryptConfig> {
   static media::mojom::DecryptConfigPtr Convert(
       const media::DecryptConfig& input);