Fix sky include guards to match Chromium style

sky/engine/core/dom/DOMSettableTokenList.h

 /*
  * Copyright (C) 2010 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 INC. 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 INC. 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 DOMSettableTokenList_h
-#define DOMSettableTokenList_h
+#ifndef SKY_ENGINE_CORE_DOM_DOMSETTABLETOKENLIST_H_
+#define SKY_ENGINE_CORE_DOM_DOMSETTABLETOKENLIST_H_
 
 #include "sky/engine/core/dom/DOMTokenList.h"
 #include "sky/engine/core/dom/SpaceSplitString.h"
 #include "sky/engine/platform/heap/Handle.h"
 #include "sky/engine/wtf/RefCounted.h"
 #include "sky/engine/wtf/text/AtomicString.h"
 
 namespace blink {
 
 class ExceptionState;
@@ skipping 36 matching lines @@
     virtual void addInternal(const AtomicString&) override;
     virtual bool containsInternal(const AtomicString&) const override;
     virtual void removeInternal(const AtomicString&) override;
 
     AtomicString m_value;
     SpaceSplitString m_tokens;
 };
 
 } // namespace blink
 
-#endif // DOMSettableTokenList_h
+#endif  // SKY_ENGINE_CORE_DOM_DOMSETTABLETOKENLIST_H_