Allow assertions to be enabled in Blink Release builds.

Source/wtf/ThreadRestrictionVerifier.h

 /*
  * 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 13 matching lines @@
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef ThreadRestrictionVerifier_h
 #define ThreadRestrictionVerifier_h
 
-#ifndef NDEBUG
+#include "wtf/Assertions.h"
 
-#include "wtf/Assertions.h"
+#if ENABLE(ASSERT)
+
 #include "wtf/Threading.h"
 
 namespace WTF {
 
 // Verifies that a class is used in a way that respects its lack of thread-safety.
 // The default mode is to verify that the object will only be used on a single thread. The
 // thread gets captured when setShared(true) is called.
 // The mode may be changed by calling useMutexMode (or turnOffVerification).
 class ThreadRestrictionVerifier {
 public:
     ThreadRestrictionVerifier()
         : m_shared(false)
         , m_owningThread(0)
     {
     }
 
     // Indicates that the object may (or may not) be owned by more than one place.
     void setShared(bool shared)
     {
-#if ENABLE(ASSERT)
         bool previouslyShared = m_shared;
-#endif
         m_shared = shared;
 
         if (!m_shared)
             return;
 
         ASSERT(shared != previouslyShared);
         // Capture the current thread to verify that subsequent ref/deref happen on this thread.
         m_owningThread = currentThread();
     }
 
     // Is it OK to use the object at this moment on the current thread?
     bool isSafeToUse() const
     {
         if (!m_shared)
             return true;
 
         return m_owningThread == currentThread();
     }
 
 private:
     bool m_shared;
 
     // Used by SingleThreadVerificationMode
     ThreadIdentifier m_owningThread;
 };
 
 }
 
-#endif // !NDEBUG
+#endif // ENABLE(ASSERT)
 #endif // ThreadRestrictionVerifier_h