Fix sky include guards to match Chromium style

sky/engine/public/platform/WebExternalTextureLayer.h

 /*
  * Copyright (C) 2011 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:
  *
  * 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 AND ITS CONTRIBUTORS "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 OR ITS 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 WebExternalTextureLayer_h
-#define WebExternalTextureLayer_h
+#ifndef SKY_ENGINE_PUBLIC_PLATFORM_WEBEXTERNALTEXTURELAYER_H_
+#define SKY_ENGINE_PUBLIC_PLATFORM_WEBEXTERNALTEXTURELAYER_H_
 
 #include "sky/engine/public/platform/WebCommon.h"
 #include "sky/engine/public/platform/WebFloatRect.h"
 #include "sky/engine/public/platform/WebLayer.h"
 
 namespace blink {
 
 class WebExternalTextureLayerClient;
 
 // This class represents a layer that renders a texture that is generated
@@ skipping 21 matching lines @@
     // at draw time. Defaults to false.
     virtual void setBlendBackgroundColor(bool) = 0;
 
     // Sets whether this context should be rate limited by the compositor. Rate limiting works by blocking
     // invalidate() and invalidateRect() calls if the compositor is too many frames behind.
     virtual void setRateLimitContext(bool) = 0;
 };
 
 } // namespace blink
 
-#endif // WebExternalTextureLayer_h
+#endif  // SKY_ENGINE_PUBLIC_PLATFORM_WEBEXTERNALTEXTURELAYER_H_