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

test/webkit/fast/js/kde/crash-2.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 13 matching lines @@
 description("KDE JS Test");
 // infinite recursion 2
 function foo() {
    foo();
 }
 
 try {
   foo();
 } catch (e) {
   debug("OK. Caught an exception");
-}
+}