Fix sky include guards to match Chromium style

sky/engine/core/rendering/RenderHTMLCanvas.h

 /*
  * Copyright (C) 2004, 2006, 2007, 2009 Apple 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 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 RenderHTMLCanvas_h
-#define RenderHTMLCanvas_h
+#ifndef SKY_ENGINE_CORE_RENDERING_RENDERHTMLCANVAS_H_
+#define SKY_ENGINE_CORE_RENDERING_RENDERHTMLCANVAS_H_
 
 #include "sky/engine/core/rendering/RenderReplaced.h"
 
 namespace blink {
 
 class HTMLCanvasElement;
 
 class RenderHTMLCanvas final : public RenderReplaced {
 public:
     explicit RenderHTMLCanvas(HTMLCanvasElement*);
 
     virtual bool isCanvas() const override { return true; }
     virtual LayerType layerTypeRequired() const override;
 
     void canvasSizeChanged();
 
 private:
     virtual const char* renderName() const override { return "RenderHTMLCanvas"; }
     virtual void paintReplaced(PaintInfo&, const LayoutPoint&) override;
     virtual void intrinsicSizeChanged() override { canvasSizeChanged(); }
 
     virtual CompositingReasons additionalCompositingReasons() const override;
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderHTMLCanvas, isCanvas());
 
 } // namespace blink
 
-#endif // RenderHTMLCanvas_h
+#endif  // SKY_ENGINE_CORE_RENDERING_RENDERHTMLCANVAS_H_