Fix sky include guards to match Chromium style

sky/engine/core/html/HTMLImageElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google 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 HTMLImageElement_h
-#define HTMLImageElement_h
+#ifndef SKY_ENGINE_CORE_HTML_HTMLIMAGEELEMENT_H_
+#define SKY_ENGINE_CORE_HTML_HTMLIMAGEELEMENT_H_
 
 #include "sky/engine/core/html/HTMLElement.h"
 #include "sky/engine/core/html/HTMLImageLoader.h"
 #include "sky/engine/core/html/canvas/CanvasImageSource.h"
 #include "sky/engine/platform/graphics/GraphicsTypes.h"
 #include "sky/engine/wtf/WeakPtr.h"
 
 namespace blink {
 
 class ImageCandidate;
@@ skipping 78 matching lines @@
     float m_imageDevicePixelRatio;
     unsigned m_elementCreatedByParser : 1;
     // Intrinsic sizing is viewport dependant if the 'w' descriptor was used for the picked resource.
     unsigned m_intrinsicSizingViewportDependant : 1;
     // Effective size is viewport dependant if the sizes attribute's effective size used v* length units.
     unsigned m_effectiveSizeViewportDependant : 1;
 };
 
 } // namespace blink
 
-#endif // HTMLImageElement_h
+#endif  // SKY_ENGINE_CORE_HTML_HTMLIMAGEELEMENT_H_