Fix sky include guards to match Chromium style

sky/engine/core/fetch/ImageResource.h

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007 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 ImageResource_h
-#define ImageResource_h
+#ifndef SKY_ENGINE_CORE_FETCH_IMAGERESOURCE_H_
+#define SKY_ENGINE_CORE_FETCH_IMAGERESOURCE_H_
 
 #include "sky/engine/core/fetch/ResourcePtr.h"
 #include "sky/engine/platform/geometry/IntRect.h"
 #include "sky/engine/platform/geometry/IntSizeHash.h"
 #include "sky/engine/platform/geometry/LayoutSize.h"
 #include "sky/engine/platform/graphics/ImageObserver.h"
 #include "sky/engine/wtf/HashMap.h"
 
 namespace blink {
 
@@ skipping 88 matching lines @@
 
     RefPtr<blink::Image> m_image;
     bool m_loadingMultipartContent;
     bool m_hasDevicePixelRatioHeaderValue;
 };
 
 DEFINE_RESOURCE_TYPE_CASTS(Image);
 
 }
 
-#endif
+#endif  // SKY_ENGINE_CORE_FETCH_IMAGERESOURCE_H_