Oilpan: fix (release) builds after r180088.

Source/core/inspector/AsyncCallStackTracker.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 41 matching lines @@
 static const char enqueueMutationRecordName[] = "Mutation";
 
 }
 
 namespace blink {
 
 void AsyncCallStackTracker::ExecutionContextData::contextDestroyed()
 {
     ASSERT(executionContext());
     OwnPtrWillBeRawPtr<ExecutionContextData> self = m_tracker->m_executionContextDataMap.take(executionContext());
-    ASSERT(self == this);
+    ASSERT_UNUSED(self, self == this);
     ContextLifecycleObserver::contextDestroyed();
 }
 
 int AsyncCallStackTracker::ExecutionContextData::circularSequentialID()
 {
     ++m_circularSequentialID;
     if (m_circularSequentialID <= 0)
         m_circularSequentialID = 1;
     return m_circularSequentialID;
 }
@@ skipping 393 matching lines @@
 
 void AsyncCallStackTracker::trace(Visitor* visitor)
 {
     visitor->trace(m_currentAsyncCallChain);
 #if ENABLE(OILPAN)
     visitor->trace(m_executionContextDataMap);
 #endif
 }
 
 } // namespace blink