Fix sky include guards to match Chromium style

sky/engine/public/platform/WebConvertableToTraceFormat.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef WebConvertableToTraceFormat_h
-#define WebConvertableToTraceFormat_h
+#ifndef SKY_ENGINE_PUBLIC_PLATFORM_WEBCONVERTABLETOTRACEFORMAT_H_
+#define SKY_ENGINE_PUBLIC_PLATFORM_WEBCONVERTABLETOTRACEFORMAT_H_
 
 #include "sky/engine/public/platform/WebPrivatePtr.h"
 #include "sky/engine/public/platform/WebString.h"
 
 namespace blink {
 
 namespace TraceEvent {
 class ConvertableToTraceFormat;
 }
 
@@ skipping 15 matching lines @@
         assign(r);
         return *this;
     }
 
 private:
     WebPrivatePtr<TraceEvent::ConvertableToTraceFormat> m_private;
 };
 
 } // namespace blink
 
-#endif
+#endif  // SKY_ENGINE_PUBLIC_PLATFORM_WEBCONVERTABLETOTRACEFORMAT_H_