Oilpan: Prepare to make ExecutionContext GarbageCollectedMixin.

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 49 matching lines @@
     {
         m_scope.scriptState()->setExecutionContext(0);
     }
 
     v8::Isolate* isolate() const { return m_scope.isolate(); }
     ScriptState* scriptState() const { return m_scope.scriptState(); }
     ExecutionContext* executionContext() { return m_scope.scriptState()->executionContext(); }
 
 private:
     V8TestingScope m_scope;
-    RefPtr<ExecutionContext> m_executionContext;
+    RefPtrWillBePersistent<ExecutionContext> m_executionContext;
 };
 
 class FakeWebIDBDatabase FINAL : public blink::WebIDBDatabase {
 public:
     static PassOwnPtr<FakeWebIDBDatabase> create() { return adoptPtr(new FakeWebIDBDatabase()); }
 
     virtual void commit(long long transactionId) OVERRIDE { }
     virtual void abort(long long transactionId) OVERRIDE { }
     virtual void close() OVERRIDE { }
 
@@ skipping 72 matching lines @@
     // 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.
     Heap::collectAllGarbage();
     EXPECT_EQ(0u, set.size());
 }
 
 } // namespace