Change WTF::TemporaryChange to be an alias for AutoReset

third_party/WebKit/Source/wtf/TemporaryChange.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:
- *
- * 1.  Redistributions of source code must retain the above copyright
- *     notice, this list of conditions and the following disclaimer.
- * 2.  Redistributions in binary form must reproduce the above copyright
- *     notice, this list of conditions and the following disclaimer in the
- *     documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
- * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT 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 TemporaryChange_h
-#define TemporaryChange_h
-
-#include "wtf/Noncopyable.h"
-
-namespace WTF {
-
-// TemporaryChange<> is useful for setting a variable to a new value only within a
-// particular scope. An TemporaryChange<> object changes a variable to its original
-// value upon destruction, making it an alternative to writing "var = false;"
-// or "var = oldVal;" at all of a block's exit points.
-//
-// This should be obvious, but note that an TemporaryChange<> instance should have a
-// shorter lifetime than its scopedVariable, to prevent invalid memory writes
-// when the TemporaryChange<> object is destroyed.
-
-template<typename T>
-class TemporaryChange {
-    WTF_MAKE_NONCOPYABLE(TemporaryChange);
-public:
-    TemporaryChange(T& scopedVariable, T newValue)
-        : m_scopedVariable(scopedVariable)
-        , m_originalValue(scopedVariable)
-    {
-        m_scopedVariable = newValue;
-    }
-
-    ~TemporaryChange()
-    {
-        m_scopedVariable = m_originalValue;
-    }
-
-
-private:
-    T& m_scopedVariable;
-    T m_originalValue;
-};
-
-} // namespace WTF
-
-using WTF::TemporaryChange;
-
-#endif