Fix some license headers in tools/

tools/playback_benchmark/common.js

-// Copyright 2010 Google Inc. All Rights Reserved.
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
 
 /**
  * @fileoverview Classes and functions used during recording and playback.
  */
 
 var Benchmark = Benchmark || {};
 
 Benchmark.functionList = [
   ['setTimeout', 'setTimeout'],
   ['clearTimeout', 'clearTimeout'],
@@ skipping 296 matching lines @@
 Benchmark.die = function(message) {
   // Debugging stuff.
   var position = top.Benchmark.playback ? top.Benchmark.agent.timelinePosition :
                  top.Benchmark.agent.timeline.length;
   message = message + ' at position ' + position;
   console.error(message);
   Benchmark.post({error: message});
   console.log(Benchmark.originals.setTimeout.call(window, function() {}, 9999));
   try { (0)() } catch(ex) { console.error(ex.stack); }
   throw message;
-};
+};