IndexedDB: Prevent terminated worker from hanging connections

Source/modules/indexeddb/IDBTransactionTest.cpp

 /*
  * Copyright (C) 2013 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 127 matching lines @@
 
     // IDBDatabase's reference
     EXPECT_EQ(1, transactionPtr->refCount());
 
     // Stop the context, so events don't get queued (which would keep the transaction alive).
     executionContext()->stopActiveDOMObjects();
 
     // Fire an abort to make sure this doesn't free the transaction during use. The test
     // will not fail if it is, but ASAN would notice the error.
     db->onAbort(transactionId, DOMError::create(AbortError, "Aborted"));
+
+    // onAbort() should have cleared the transaction's reference to the database.
+    EXPECT_EQ(1, db->refCount());
 }
 
 } // namespace