Bug 1583251 - P3 - Check if it is okay to allow shared memory while deserializing; r=nika,lth

Differential Revision: https://phabricator.services.mozilla.com/D48349

dom/base/PostMessageEvent.cpp

@@ -162,7 +162,6 @@ PostMessageEvent::Run() {
   nsCOMPtr<mozilla::dom::EventTarget> eventTarget =
       do_QueryObject(targetWindow);
 
-  // XXX cloneDataPolicy will be used in P3
   JS::CloneDataPolicy cloneDataPolicy;
   MOZ_DIAGNOSTIC_ASSERT(targetWindow);
   if (mCallerAgentClusterId.isSome() &&
@@ -172,8 +171,8 @@ PostMessageEvent::Run() {
 
   StructuredCloneHolder* holder;
   if (mHolder.constructed<StructuredCloneHolder>()) {
-    mHolder.ref<StructuredCloneHolder>().Read(ToSupports(targetWindow), cx,
-                                              &messageData, rv);
+    mHolder.ref<StructuredCloneHolder>().Read(
+        ToSupports(targetWindow), cx, &messageData, cloneDataPolicy, rv);
     holder = &mHolder.ref<StructuredCloneHolder>();
   } else {
     MOZ_ASSERT(mHolder.constructed<ipc::StructuredCloneData>());