Fix license headers in a number of files

ppapi/native_client/src/trusted/plugin/dylib_unittest.cc

-// Copyright 2011 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.
+// 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 "native_client/src/trusted/plugin/dylib_unittest.h"
 
 #include <stdio.h>
 
 #if NACL_WINDOWS
 DylibHandle DylibOpen(const char* lib_path) {
   return LoadLibrary(lib_path);
 }
 
@@ skipping 18 matching lines @@
 SymbolHandle GetSymbolHandle(DylibHandle dl_handle, const char* name) {
   void* sym_handle = dlsym(dl_handle, name);
   char* error_string = dlerror();
   if (sym_handle == NULL || error_string != NULL) {
     fprintf(stderr, "Couldn't get symbol %s: %s\n", name, error_string);
     sym_handle = NULL;
   }
   return reinterpret_cast<SymbolHandle>(sym_handle);
 }
 #endif