Add support for loading pak files from arbitrary file regions.

base/base.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'includes': [
     '../build/win_precompile.gypi',
@@ skipping 446 matching lines @@
         'deferred_sequenced_task_runner_unittest.cc',
         'environment_unittest.cc',
         'file_util_unittest.cc',
         'file_version_info_unittest.cc',
         'files/dir_reader_posix_unittest.cc',
         'files/file_path_unittest.cc',
         'files/file_proxy_unittest.cc',
         'files/file_unittest.cc',
         'files/file_util_proxy_unittest.cc',
         'files/important_file_writer_unittest.cc',
+        'files/memory_mapped_file_unittest.cc',
         'files/scoped_temp_dir_unittest.cc',
         'gmock_unittest.cc',
         'guid_unittest.cc',
         'hash_unittest.cc',
         'id_map_unittest.cc',
         'i18n/break_iterator_unittest.cc',
         'i18n/char_iterator_unittest.cc',
         'i18n/case_conversion_unittest.cc',
         'i18n/file_util_icu_unittest.cc',
         'i18n/icu_string_conversions_unittest.cc',
@@ skipping 1024 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],
 }