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

test/webkit/fast/js/kde/operators.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 483 matching lines @@
 
 shouldBeUndefined("void 1");
 
 shouldBeTrue("1 in [1, 2]");
 shouldBeFalse("3 in [1, 2]");
 shouldBeTrue("'a' in { a:1, b:2 }");
 
 // instanceof
 // Those 2 lines don't parse in Netscape...
 shouldBe("(new Boolean()) instanceof Boolean", "true");
-shouldBe("(new Boolean()) instanceof Number", "false");
+shouldBe("(new Boolean()) instanceof Number", "false");