Move deprecation messages to UseCounter::measureDeprecatedFeature.

Source/core/html/HTMLMediaElement.idl

Index: Source/core/html/HTMLMediaElement.idl
diff --git a/Source/core/html/HTMLMediaElement.idl b/Source/core/html/HTMLMediaElement.idl
index ff2a8a0e178216928913dfe890b08c3048d432a2..0dbe3edca2f7e6df1eb1f1da367bdebe897f901e 100644
--- a/Source/core/html/HTMLMediaElement.idl
+++ b/Source/core/html/HTMLMediaElement.idl
@@ -93,8 +93,14 @@ readonly attribute unsigned long webkitAudioDecodedByteCount;
 readonly attribute unsigned long webkitVideoDecodedByteCount;
 
 #if defined(ENABLE_ENCRYPTED_MEDIA) && ENABLE_ENCRYPTED_MEDIA
+
+#if defined(ENABLE_ENCRYPTED_MEDIA_V2) && ENABLE_ENCRYPTED_MEDIA_V2
+[EnabledAtRuntime=encryptedMedia, RaisesException, DeprecateAs=PrefixedMediaGenerateKeyRequest] void webkitGenerateKeyRequest([TreatNullAs=NullString, TreatUndefinedAs=NullString] DOMString keySystem, optional Uint8Array initData);
+[EnabledAtRuntime=encryptedMedia, RaisesException, DeprecateAs=PrefixedMediaAddKey] void webkitAddKey([TreatNullAs=NullString, TreatUndefinedAs=NullString] DOMString keySystem, Uint8Array key, optional Uint8Array initData, [Default=NullString] optional DOMString sessionId);
+#else
 [EnabledAtRuntime=encryptedMedia, RaisesException] void webkitGenerateKeyRequest([TreatNullAs=NullString, TreatUndefinedAs=NullString] DOMString keySystem, optional Uint8Array initData);
 [EnabledAtRuntime=encryptedMedia, RaisesException] void webkitAddKey([TreatNullAs=NullString, TreatUndefinedAs=NullString] DOMString keySystem, Uint8Array key, optional Uint8Array initData, [Default=NullString] optional DOMString sessionId);
+#endif
 [EnabledAtRuntime=encryptedMedia, RaisesException] void webkitCancelKeyRequest([TreatNullAs=NullString, TreatUndefinedAs=NullString] DOMString keySystem, [Default=NullString] optional DOMString sessionId);
 
     [EnabledAtRuntime=encryptedMedia] attribute EventListener onwebkitkeyadded;