IndexedDB: Ensure transactions created in microtasks are deactivated

Source/bindings/v8/V8RecursionScope.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 20 matching lines @@
 #include "config.h"
 #include "bindings/v8/V8RecursionScope.h"
 
 #include "core/dom/Microtask.h"
 #include "modules/indexeddb/IDBPendingTransactionMonitor.h"
 
 namespace WebCore {
 
 void V8RecursionScope::didLeaveScriptContext()
 {
-    // FIXME: Instrument any work that takes place when script exits to c++ (e.g. Mutation Observers).
+    Microtask::performCheckpoint();
 
     // Indexed DB requires that transactions are created with an internal |active| flag
     // set to true, but the flag becomes false when control returns to the event loop.
     IDBPendingTransactionMonitor::from(m_executionContext).deactivateNewTransactions();
-
-    Microtask::performCheckpoint();
 }
 
 } // namespace WebCore