Fix sky include guards to match Chromium style

sky/engine/core/rendering/style/StyleGeneratedImage.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
-#ifndef StyleGeneratedImage_h
-#define StyleGeneratedImage_h
+#ifndef SKY_ENGINE_CORE_RENDERING_STYLE_STYLEGENERATEDIMAGE_H_
+#define SKY_ENGINE_CORE_RENDERING_STYLE_STYLEGENERATEDIMAGE_H_
 
 #include "sky/engine/core/rendering/style/StyleImage.h"
 
 namespace blink {
 
 class CSSValue;
 class CSSImageGeneratorValue;
 
 class StyleGeneratedImage final : public StyleImage {
 public:
@@ skipping 20 matching lines @@
 private:
     StyleGeneratedImage(PassRefPtr<CSSImageGeneratorValue>);
 
     // FIXME: oilpan: change to member once StyleImage is moved to the oilpan heap
     RefPtr<CSSImageGeneratorValue> m_imageGeneratorValue;
     IntSize m_containerSize;
     bool m_fixedSize;
 };
 
 }
-#endif
+#endif  // SKY_ENGINE_CORE_RENDERING_STYLE_STYLEGENERATEDIMAGE_H_