Bug 1768922 - Support ESM loaded by shim in Cu.isModuleLoaded. r=yulia

Differential Revision: https://phabricator.services.mozilla.com/D146166

js/loader/ModuleLoaderBase.h

@@ -16,8 +16,8 @@
 #include "nsRefPtrHashtable.h"
 #include "nsCOMArray.h"
 #include "nsCOMPtr.h"
-#include "nsILoadInfo.h"  // nsSecurityFlags
-#include "nsINode.h"      // nsIURI
+#include "nsILoadInfo.h"    // nsSecurityFlags
+#include "nsINode.h"        // nsIURI
 #include "nsThreadUtils.h"  // GetMainThreadSerialEventTarget
 #include "nsURIHashKey.h"
 #include "mozilla/CORSMode.h"
@@ -274,6 +274,9 @@ class ModuleLoaderBase : public nsISupports {
     mAcquiringImportMaps = acquiring;
   }
 
+  // Returns true if the module for given URL is already fetched.
+  bool IsModuleFetched(nsIURI* aURL) const;
+
   // Internal methods.
 
  private: