Fix sky include guards to match Chromium style

sky/engine/core/html/HTMLCanvasElement.h

 /*
  * Copyright (C) 2004, 2006, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. 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 COMPUTER, INC. ``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 COMPUTER, INC. OR
  * 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 HTMLCanvasElement_h
-#define HTMLCanvasElement_h
+#ifndef SKY_ENGINE_CORE_HTML_HTMLCANVASELEMENT_H_
+#define SKY_ENGINE_CORE_HTML_HTMLCANVASELEMENT_H_
 
 #include "base/cancelable_callback.h"
 #include "sky/engine/core/dom/Document.h"
 #include "sky/engine/core/html/HTMLElement.h"
 #include "sky/engine/core/html/canvas/CanvasImageSource.h"
 #include "sky/engine/platform/geometry/FloatRect.h"
 #include "sky/engine/platform/geometry/IntSize.h"
 #include "sky/engine/platform/graphics/Canvas2DLayerBridge.h"
 #include "sky/engine/platform/graphics/GraphicsTypes.h"
 #include "sky/engine/platform/graphics/ImageBufferClient.h"
@@ skipping 148 matching lines @@
     mutable bool m_didClearImageBuffer;
     OwnPtr<ImageBuffer> m_imageBuffer;
     mutable OwnPtr<GraphicsContextStateSaver> m_contextStateSaver;
 
     mutable RefPtr<Image> m_presentedImage;
     mutable RefPtr<Image> m_copiedImage; // FIXME: This is temporary for platforms that have to copy the image buffer to render (and for CSSCanvasValue).
 };
 
 } // namespace blink
 
-#endif // HTMLCanvasElement_h
+#endif  // SKY_ENGINE_CORE_HTML_HTMLCANVASELEMENT_H_