Make sure files end with exactly one new line and police this in presubmit.

test/webkit/fast/js/kde/Array.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple 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
@@ skipping 215 matching lines @@
   } catch (e) {
     caught = true;
   }
   shouldBeTrue("caught");
 
   // restore
   Number.prototype.toString = backupNumberToString;
   Number.prototype.toLocaleString = backupNumberToLocaleString;
   RegExp.prototype.toString = backupRegExpToString;
   RegExp.prototype.toLocaleString = backupRegExpToLocaleString;
-}
+}