Bug 1759881 - Part 5: Remove microtask checkpoints from the module loader in couple of places r=smaug

This removes the microtask checkpoint when instantiating modules and moves the
one when creating a module script to the the script loader.

Differential Revision: https://phabricator.services.mozilla.com/D141252

dom/base/nsJSUtils.cpp

@@ -148,8 +148,6 @@ nsresult nsJSUtils::ModuleInstantiate(JSContext* aCx,
 
   MOZ_ASSERT(aCx == nsContentUtils::GetCurrentJSContext());
   MOZ_ASSERT(NS_IsMainThread());
-  MOZ_ASSERT(CycleCollectedJSContext::Get() &&
-             CycleCollectedJSContext::Get()->MicroTaskLevel());
 
   NS_ENSURE_TRUE(xpc::Scriptability::Get(aModule).Allowed(), NS_OK);
 

dom/script/ScriptLoader.cpp

@@ -1106,6 +1106,13 @@ bool ScriptLoader::ProcessInlineScript(nsIScriptElement* aElement,
       }
     }
 
+    {
+      // We must perform a microtask checkpoint when inserting script elements
+      // as specified by: https://html.spec.whatwg.org/#parsing-main-incdata
+      // For the non-inline module cases this happens in ProcessRequest.
+      mozilla::nsAutoMicroTask mt;
+    }
+
     nsresult rv = mModuleLoader->ProcessFetchedModuleSource(modReq);
     if (NS_FAILED(rv)) {
       ReportErrorToConsole(modReq, rv);

js/loader/ModuleLoaderBase.cpp

@@ -241,8 +241,6 @@ nsresult ModuleLoaderBase::CreateModuleScript(ModuleLoadRequest* aRequest) {
     return NS_ERROR_FAILURE;
   }
 
-  mozilla::nsAutoMicroTask mt;
-
   mozilla::dom::AutoJSAPI jsapi;
   if (!jsapi.Init(globalObject)) {
     return NS_ERROR_FAILURE;
@@ -688,7 +686,6 @@ bool ModuleLoaderBase::InstantiateModuleTree(ModuleLoadRequest* aRequest) {
 
   MOZ_ASSERT(moduleScript->ModuleRecord());
 
-  mozilla::nsAutoMicroTask mt;
   mozilla::dom::AutoJSAPI jsapi;
   if (NS_WARN_IF(!jsapi.Init(moduleScript->ModuleRecord()))) {
     return false;