Bug 902901 - Give nsScriptElement.h an include guard; r=hsivonen

content/base/src/nsScriptElement.h

@@ -2,6 +2,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+#ifndef nsScriptElement_h
+#define nsScriptElement_h
+
 #include "mozilla/Attributes.h"
 #include "nsIScriptLoaderObserver.h"
 #include "nsIScriptElement.h"
@@ -43,3 +46,5 @@ protected:
 
   virtual bool MaybeProcessScript() MOZ_OVERRIDE;
 };
+
+#endif // nsScriptElement_h