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

test/webkit/try-catch-try-try-catch-try-finally-return-catch-finally.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 32 matching lines @@
     } finally {
         z
     }
 }
 
 try {
     foo();
 } catch (e) {
     testPassed("It worked.");
 }
-