Fix sky include guards to match Chromium style

sky/engine/platform/graphics/Canvas2DImageBufferSurface.h

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 10 matching lines @@
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER 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 Canvas2DImageBufferSurface_h
-#define Canvas2DImageBufferSurface_h
+#ifndef SKY_ENGINE_PLATFORM_GRAPHICS_CANVAS2DIMAGEBUFFERSURFACE_H_
+#define SKY_ENGINE_PLATFORM_GRAPHICS_CANVAS2DIMAGEBUFFERSURFACE_H_
 
 #include "sky/engine/platform/graphics/Canvas2DLayerBridge.h"
 #include "sky/engine/platform/graphics/ImageBufferSurface.h"
 
 namespace blink {
 
 // This shim necessary because ImageBufferSurfaces are not allowed to be RefCounted
 class Canvas2DImageBufferSurface final : public ImageBufferSurface {
 public:
     Canvas2DImageBufferSurface(const IntSize& size, OpacityMode opacityMode = NonOpaque, int msaaSampleCount = 1)
@@ skipping 20 matching lines @@
     virtual bool isAccelerated() const override { return m_layerBridge->isAccelerated(); }
     virtual void setIsHidden(bool hidden) override { m_layerBridge->setIsHidden(hidden); }
     virtual void setImageBuffer(ImageBuffer* imageBuffer) override { m_layerBridge->setImageBuffer(imageBuffer); }
 
 private:
     RefPtr<Canvas2DLayerBridge> m_layerBridge;
 };
 
 } // namespace blink
 
-#endif
+#endif  // SKY_ENGINE_PLATFORM_GRAPHICS_CANVAS2DIMAGEBUFFERSURFACE_H_