Fix some license headers in tools/

tools/playback_benchmark/common.js

Index: tools/playback_benchmark/common.js
diff --git a/tools/playback_benchmark/common.js b/tools/playback_benchmark/common.js
index 801d602c3a4d9d41b691999660b74d4ed84ca533..69309aac06b843e0503d19154eebdff437b86709 100644
--- a/tools/playback_benchmark/common.js
+++ b/tools/playback_benchmark/common.js
@@ -1,4 +1,6 @@
-// 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.
@@ -315,4 +317,4 @@ Benchmark.die = function(message) {
   console.log(Benchmark.originals.setTimeout.call(window, function() {}, 9999));
   try { (0)() } catch(ex) { console.error(ex.stack); }
   throw message;
-};
+};