Bug 1916277 - Part 8: Set mIsPreload to true for non-top-level modules. r=jonco

Currently Gecko only set mIsPreload to true for the top-level preloading
load. To identify a non-top-level preload, update mIsPreload accordingly
to match the mIsPreload flag from the root module.

Differential Revision: https://phabricator.services.mozilla.com/D281154

Author: allstarschh

dom/script/ModuleLoader.cpp

@@ -498,6 +498,9 @@ already_AddRefed<ModuleLoadRequest> ModuleLoader::CreateRequest(
     MOZ_ASSERT(root);
     LoadContextBase* loadContext = root->mLoadContext;
     context->mScriptMode = loadContext->AsWindowContext()->mScriptMode;
+    if (loadContext->AsWindowContext()->mIsPreload) {
+      context->mIsPreload = true;
+    }
     kind = ModuleLoadRequest::Kind::StaticImport;
   }
 

dom/script/ScriptLoadContext.h

@@ -286,7 +286,7 @@ class ScriptLoadContext : public JS::loader::LoadContextBase,
   bool mInCompilingList;  // True if we are in mOffThreadCompilingRequests.
   bool mWasCompiledOMT;   // True if the script has been compiled off main
                           // thread.
-  // Set on scripts and top level modules.
+  // Set on preloading scripts or modules.
   bool mIsPreload;
 
   // For preload requests, we defer reporting errors to the console until the

js/loader/ModuleLoadRequest.cpp

@@ -97,6 +97,10 @@ void ModuleLoadRequest::ModuleLoaded() {
   MOZ_ASSERT(IsFetching());
 
   mModuleScript = mLoader->GetFetchedModule(ModuleMapKey(URI(), mModuleType));
+
+  if (mModuleScript->ForPreload() != mLoadContext->IsPreload()) {
+    mModuleScript->SetForPreload(mLoadContext->IsPreload());
+  }
 }
 
 void ModuleLoadRequest::LoadFailed() {