Fix license headers in a number of files

net/proxy/proxy_list_unittest.cc

-// Copyright (c) 2006-2008 The Chromium Authors. 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.
 
 #include "net/proxy/proxy_list.h"
 
 #include "net/proxy/proxy_server.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace net {
 
@@ skipping 126 matching lines @@
     list.DeprioritizeBadProxies(retry_info_map);
 
     EXPECT_EQ("PROXY foopy1:80;PROXY foopy2:80;PROXY foopy3:80",
               list.ToPacString());
   }
 }
 
 }  // namesapce
 
 }  // namespace net