Backed out changeset b246c998fb8f (bug 1786571) for causing ScriptLoader failures CLOSED TREE

dom/workers/ScriptLoader.cpp

@@ -391,10 +391,10 @@ WorkerScriptLoader::WorkerScriptLoader(
     : mOriginStack(std::move(aOriginStack)),
       mSyncLoopTarget(aSyncLoopTarget),
       mWorkerScriptType(aWorkerScriptType),
+      mCancelMainThread(Nothing()),
       mRv(aRv),
       mCleanedUp(false),
-      mCleanUpLock("cleanUpLock"),
-      mCancelMainThread(Nothing()) {
+      mCleanUpLock("cleanUpLock") {
   aWorkerPrivate->AssertIsOnWorkerThread();
   MOZ_ASSERT(aSyncLoopTarget);
 
@@ -656,9 +656,6 @@ nsresult WorkerScriptLoader::OnStreamComplete(ScriptLoadRequest* aRequest,
                                               nsresult aStatus) {
   AssertIsOnMainThread();
 
-  // We expect our callers to runtime-check this in advance.
-  MOZ_ASSERT(!IsCancelled());
-
   LoadingFinished(aRequest, aStatus);
   return NS_OK;
 }
@@ -711,9 +708,7 @@ nsresult WorkerScriptLoader::LoadScripts(
       nsresult rv = LoadScript(loadContext->mRequest);
       if (NS_WARN_IF(NS_FAILED(rv))) {
         LoadingFinished(loadContext->mRequest, rv);
-        // Let any error to be handled as if it was a fetch error when it
-        // comes time to evaluate its script from its load having completed,
-        // that is: do not CancelMainThread already here.
+        CancelMainThread(rv, &aContextList);
         return rv;
       }
     }