1 files changed, 4 insertions, 3 deletions
diff --git a/dom/media/eme/MediaKeyMessageEvent.cpp b/dom/media/eme/MediaKeyMessageEvent.cpp
index 37c509e67..289d0c16e 100644
--- a/dom/media/eme/MediaKeyMessageEvent.cpp
+++ b/dom/media/eme/MediaKeyMessageEvent.cpp
@@ -85,10 +85,11 @@ MediaKeyMessageEvent::Constructor(const GlobalObject& aGlobal,
   RefPtr<MediaKeyMessageEvent> e = new MediaKeyMessageEvent(owner);
   bool trusted = e->Init(owner);
   e->InitEvent(aType, aEventInitDict.mBubbles, aEventInitDict.mCancelable);
-  aEventInitDict.mMessage.ComputeLengthAndData();
+  nsTArray<uint8_t> initData;
+  CopyArrayBufferViewOrArrayBufferData(aEventInitDict.mMessage, initData);
   e->mMessage = ArrayBuffer::Create(aGlobal.Context(),
-                                    aEventInitDict.mMessage.Length(),
-                                    aEventInitDict.mMessage.Data());
+                                    initData.Length(),
+                                    initData.Elements());
   if (!e->mMessage) {
     aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
     return nullptr;