Bug 1257725 part 4. Get rid of ThreadsafeAutoJSContext usage in IndexedDB code, except for IDBRequest::CaptureCaller. r=khuey

dom/indexedDB/IDBDatabase.cpp

@@ -607,32 +607,16 @@ IDBDatabase::Transaction(const StringOrStringSequence& aStoreNames,
 {
   AssertIsOnOwningThread();
 
-  aRv.MightThrowJSException();
-
   if ((aMode == IDBTransactionMode::Readwriteflush ||
        aMode == IDBTransactionMode::Cleanup) &&
       !IndexedDatabaseManager::ExperimentalFeaturesEnabled()) {
     // Pretend that this mode doesn't exist. We don't have a way to annotate
     // certain enum values as depending on preferences so we just duplicate the
     // normal exception generation here.
-    ThreadsafeAutoJSContext cx;
+    aRv.ThrowTypeError<MSG_INVALID_ENUM_VALUE>(
-
+      NS_LITERAL_STRING("Argument 2 of IDBDatabase.transaction"),
-    // Disable any automatic error reporting that might be set up so that we
+      NS_LITERAL_STRING("readwriteflush"),
-    // can grab the exception object.
+      NS_LITERAL_STRING("IDBTransactionMode"));
-    AutoForceSetExceptionOnContext forceExn(cx);
-
-    MOZ_ALWAYS_FALSE(
-      ThrowErrorMessage(cx,
-                        MSG_INVALID_ENUM_VALUE,
-                        "Argument 2 of IDBDatabase.transaction",
-                        "readwriteflush",
-                        "IDBTransactionMode"));
-    MOZ_ASSERT(JS_IsExceptionPending(cx));
-
-    JS::Rooted<JS::Value> exception(cx);
-    MOZ_ALWAYS_TRUE(JS_GetPendingException(cx, &exception));
-
-    aRv.ThrowJSException(cx, exception);
     return nullptr;
   }
 

dom/indexedDB/IndexedDatabaseManager.cpp

@@ -484,8 +484,7 @@ IndexedDatabaseManager::CommonPostHandleEvent(EventChainPostVisitor& aVisitor,
     error->GetName(errorName);
   }
 
-  ThreadsafeAutoJSContext cx;
+  RootedDictionary<ErrorEventInit> init(nsContentUtils::RootingCxForThread());
-  RootedDictionary<ErrorEventInit> init(cx);
   request->GetCallerLocation(init.mFilename, &init.mLineno, &init.mColno);
 
   init.mMessage = errorName;