--- a/dom/media/eme/CDMProxy.cpp
+++ b/dom/media/eme/CDMProxy.cpp
@@ -410,16 +410,17 @@ CDMProxy::OnResolveLoadSessionPromise(ui
 }
 
 static dom::MediaKeyMessageType
 ToMediaKeyMessageType(GMPSessionMessageType aMessageType) {
   switch (aMessageType) {
     case kGMPLicenseRequest: return dom::MediaKeyMessageType::License_request;
     case kGMPLicenseRenewal: return dom::MediaKeyMessageType::License_renewal;
     case kGMPLicenseRelease: return dom::MediaKeyMessageType::License_release;
+    case kGMPIndividualizationRequest: return dom::MediaKeyMessageType::Individualization_request;
     default: return dom::MediaKeyMessageType::License_request;
   };
 };
 
 void
 CDMProxy::OnSessionMessage(const nsAString& aSessionId,
                            GMPSessionMessageType aMessageType,
                            nsTArray<uint8_t>& aMessage)

--- a/dom/media/gmp-plugin/fake.info
+++ b/dom/media/gmp-plugin/fake.info
@@ -1,5 +1,5 @@
 Name: fake
 Description: Fake GMP Plugin
 Version: 1.0
-APIs: encode-video[h264], decode-video[h264], eme-decrypt-v3[fake]
+APIs: encode-video[h264], decode-video[h264], eme-decrypt-v4[fake]
 Libraries: dxva2.dll

--- a/dom/media/gmp/gmp-api/gmp-decryption.h
+++ b/dom/media/gmp/gmp-api/gmp-decryption.h
@@ -67,17 +67,18 @@ enum GMPDOMException {
   kGMPQuotaExceededError = 22,
   kGMPTimeoutError = 23
 };
 
 enum GMPSessionMessageType {
   kGMPLicenseRequest = 0,
   kGMPLicenseRenewal = 1,
   kGMPLicenseRelease = 2,
-  kGMPMessageInvalid = 3 // Must always be last.
+  kGMPIndividualizationRequest = 3,
+  kGMPMessageInvalid = 4 // Must always be last.
 };
 
 // Time in milliseconds, as offset from epoch, 1 Jan 1970.
 typedef int64_t GMPTimestamp;
 
 // Capability definitions. The capabilities of the EME GMP are reported
 // to Gecko by calling the GMPDecryptorCallback::SetCapabilities()
 // callback and specifying the logical OR of the GMP_EME_CAP_* flags below.
@@ -214,17 +215,17 @@ public:
 };
 
 enum GMPSessionType {
   kGMPTemporySession = 0,
   kGMPPersistentSession = 1,
   kGMPSessionInvalid = 2 // Must always be last.
 };
 
-#define GMP_API_DECRYPTOR "eme-decrypt-v3"
+#define GMP_API_DECRYPTOR "eme-decrypt-v4"
 
 // API exposed by plugin library to manage decryption sessions.
 // When the Host requests this by calling GMPGetAPIFunc().
 //
 // API name macro: GMP_API_DECRYPTOR
 // Host API: GMPDecryptorHost
 class GMPDecryptor {
 public:

--- a/dom/webidl/MediaKeyMessageEvent.webidl
+++ b/dom/webidl/MediaKeyMessageEvent.webidl
@@ -8,17 +8,18 @@
  *
  * Copyright © 2014 W3C® (MIT, ERCIM, Keio, Beihang), All Rights Reserved.
  * W3C liability, trademark and document use rules apply.
  */
 
 enum MediaKeyMessageType {
   "license-request",
   "license-renewal",
-  "license-release"
+  "license-release",
+  "individualization-request"
 };
 
 [Pref="media.eme.enabled", Constructor(DOMString type, optional MediaKeyMessageEventInit eventInitDict)]
 interface MediaKeyMessageEvent : Event {
   readonly attribute MediaKeyMessageType messageType;
   [Throws]
   readonly attribute ArrayBuffer message;
 };

--- a/media/gmp-clearkey/0.1/clearkey.info
+++ b/media/gmp-clearkey/0.1/clearkey.info
@@ -1,4 +1,4 @@
 Name: clearkey
 Description: ClearKey decrypt-only GMP plugin
 Version: 0.1
-APIs: eme-decrypt-v3[org.w3.clearkey]
+APIs: eme-decrypt-v4[org.w3.clearkey]