Fix sky include guards to match Chromium style

sky/engine/platform/text/DateTimeFormat.h

 /*
  * Copyright (C) 2012 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 INC. 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 INC. 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 DateTimeFormat_h
-#define DateTimeFormat_h
+#ifndef SKY_ENGINE_PLATFORM_TEXT_DATETIMEFORMAT_H_
+#define SKY_ENGINE_PLATFORM_TEXT_DATETIMEFORMAT_H_
 
 #include "sky/engine/platform/PlatformExport.h"
 #include "sky/engine/wtf/Forward.h"
 
 namespace blink {
 
 // DateTimeFormat parses date time format defined in Unicode Technical
 // standard 35, Locale Data Markup Language (LDML)[1].
 // [1] LDML http://unicode.org/reports/tr35/tr35-6.html#Date_Format_Patterns
 class PLATFORM_EXPORT DateTimeFormat {
@@ skipping 63 matching lines @@
         virtual void visitLiteral(const String&) = 0;
     };
 
     // Returns true if succeeded, false if failed.
     static bool parse(const String&, TokenHandler&);
     static void quoteAndAppendLiteral(const String&, StringBuilder&);
 };
 
 } // namespace blink
 
-#endif // DateTimeFormat_h
+#endif  // SKY_ENGINE_PLATFORM_TEXT_DATETIMEFORMAT_H_