Fix sky include guards to match Chromium style

sky/engine/core/html/parser/HTMLParserIdioms.h

Index: sky/engine/core/html/parser/HTMLParserIdioms.h
diff --git a/sky/engine/core/html/parser/HTMLParserIdioms.h b/sky/engine/core/html/parser/HTMLParserIdioms.h
index 74859528fd5323f9ed08413e0dffc2ef2415df17..74d135cec929b31fbb4a7ab7d72be822044a59f9 100644
--- a/sky/engine/core/html/parser/HTMLParserIdioms.h
+++ b/sky/engine/core/html/parser/HTMLParserIdioms.h
@@ -22,8 +22,8 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef HTMLParserIdioms_h
-#define HTMLParserIdioms_h
+#ifndef SKY_ENGINE_CORE_HTML_PARSER_HTMLPARSERIDIOMS_H_
+#define SKY_ENGINE_CORE_HTML_PARSER_HTMLPARSERIDIOMS_H_
 
 #include "sky/engine/core/dom/QualifiedName.h"
 #include "sky/engine/platform/Decimal.h"
@@ -128,4 +128,4 @@ inline static String attemptStaticStringCreation(const String str)
 
 
 }
-#endif
+#endif  // SKY_ENGINE_CORE_HTML_PARSER_HTMLPARSERIDIOMS_H_