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

test/webkit/get-by-pname-that-looks-like-a-patchable-get-by-val.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 22 matching lines @@
         for (var s in o) {
             s = 0;
             result += o[s];
         }
     }
 
     return result;
 }
 
 shouldBe("foo()", "300");
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-