Add Promises for EME (Chromium side)

ppapi/api/private/pp_content_decryptor.idl

Index: ppapi/api/private/pp_content_decryptor.idl
diff --git a/ppapi/api/private/pp_content_decryptor.idl b/ppapi/api/private/pp_content_decryptor.idl
index 16be86edbf202f02cd1a09cc5021192b01ddd854..676470f459f64741cdb48195ab8b35c94ec96e86 100644
--- a/ppapi/api/private/pp_content_decryptor.idl
+++ b/ppapi/api/private/pp_content_decryptor.idl
@@ -399,3 +399,36 @@ enum PP_DecryptorStreamType {
   PP_DECRYPTORSTREAMTYPE_AUDIO = 0,
   PP_DECRYPTORSTREAMTYPE_VIDEO = 1
 };
+
+/**
+ * <code>PP_SessionType</code> contains session type constants.
+ */
+[assert_size(4)]
+enum PP_SessionType {
+  PP_SESSIONTYPE_TEMPORARY = 0,
+  PP_SESSIONTYPE_PERSISTENT = 1
+};
+
+/**
+ * <code>PP_ExceptionCode</code> contains exception code constants.
+ */
+[assert_size(4)]
+enum PP_ExceptionCode {
+  PP_EXCEPTIONCODE_NOMODIFICATIONALLOWEDERROR = 0,
+  PP_EXCEPTIONCODE_NOTFOUNDERROR = 1,
+  PP_EXCEPTIONCODE_NOTSUPPORTEDERROR = 2,
+  PP_EXCEPTIONCODE_INVALIDSTATEERROR = 3,
+  PP_EXCEPTIONCODE_INVALIDMODIFICATIONERROR = 4,
+  PP_EXCEPTIONCODE_INVALIDACCESSERROR = 5,
+  PP_EXCEPTIONCODE_SECURITYERROR = 6,
+  PP_EXCEPTIONCODE_ABORTERROR = 7,
+  PP_EXCEPTIONCODE_QUOTAEXCEEDEDERROR = 8,
+  PP_EXCEPTIONCODE_TIMEOUTERROR = 9,
+  PP_EXCEPTIONCODE_UNKNOWNERROR = 10,
+  PP_EXCEPTIONCODE_DATAERROR = 11,
+  PP_EXCEPTIONCODE_VERSIONERROR = 12,
+  PP_EXCEPTIONCODE_NOTREADABLEERROR = 13,
+  PP_EXCEPTIONCODE_OPERATIONERROR = 14,
+  PP_EXCEPTIONCODE_CLIENTERROR = 15,
+  PP_EXCEPTIONCODE_OUTPUTERROR = 16
+};