Add FileReaderInterface. Move StringFileWriter to StringFile and

util/util.gyp

 # Copyright 2014 The Crashpad Authors. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 12 matching lines @@
       ],
       'include_dirs': [
         '..',
         '<(INTERMEDIATE_DIR)',
       ],
       'sources': [
         'file/file_io.cc',
         'file/file_io.h',
         'file/file_io_posix.cc',
         'file/file_io_win.cc',
+        'file/file_reader.cc',
+        'file/file_reader.h',
+        'file/file_seeker.h',
         'file/file_writer.cc',
         'file/file_writer.h',
-        'file/string_file_writer.cc',
-        'file/string_file_writer.h',
+        'file/string_file.cc',
+        'file/string_file.h',
         'mac/checked_mach_address_range.cc',
         'mac/checked_mach_address_range.h',
         'mac/launchd.h',
         'mac/launchd.mm',
         'mac/mac_util.cc',
         'mac/mac_util.h',
         'mac/service_management.cc',
         'mac/service_management.h',
         'mac/xattr.cc',
         'mac/xattr.h',
@@ skipping 204 matching lines @@
         '../compat/compat.gyp:compat',
         '../third_party/gmock/gmock.gyp:gmock',
         '../third_party/gtest/gtest.gyp:gtest',
         '../third_party/gtest/gtest.gyp:gtest_main',
         '../third_party/mini_chromium/mini_chromium/base/base.gyp:base',
       ],
       'include_dirs': [
         '..',
       ],
       'sources': [
-        'file/string_file_writer_test.cc',
+        'file/string_file_test.cc',
         'mac/checked_mach_address_range_test.cc',
         'mac/launchd_test.mm',
         'mac/mac_util_test.mm',
         'mac/service_management_test.mm',
         'mac/xattr_test.cc',
         'mach/child_port_handshake_test.cc',
         'mach/child_port_server_test.cc',
         'mach/composite_mach_message_server_test.cc',
         'mach/exc_client_variants_test.cc',
         'mach/exc_server_variants_test.cc',
@@ skipping 43 matching lines @@
     },
     {
       'target_name': 'util_test_multiprocess_exec_test_child',
       'type': 'executable',
       'sources': [
         'test/multiprocess_exec_test_child.cc',
       ],
     },
   ],
 }