Copy the relevant parts of ICU to a new file base/third_party/icu/icu_utf.*
so we can do basic UTF8/16/32 conversions without linking all of ICU.

Change callers who used to call SysUTF8ToWide/SysWideToUTF8 in base to using
these new functions. I will remove the Sys versions of these functions in a
later patch.

TEST=none
BUG=none
Review URL: http://codereview.chromium.org/243102

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@28219 0039d316-1c4b-4281-b951-d872f2087c98

• base/base.gyp[diff]
• base/file_util.cc[diff]
• base/file_util_posix.cc[diff]
• base/file_util_unittest.cc[diff]
• base/file_version_info_mac.mm[diff]
• base/i18n/icu_string_conversions.cc[Added - diff]
• base/i18n/icu_string_conversions.h[Added - diff]
• base/i18n/string_conversions.cc[Deleted - diff]
• base/i18n/string_conversions.h[Deleted - diff]
• base/json_reader.cc[diff]
• base/json_writer.cc[diff]
• base/logging.cc[diff]
• base/platform_file_posix.cc[diff]
• base/process_util_mac.mm[diff]
• base/stats_table.cc[diff]
• base/string16.cc[diff]
• base/string16_unittest.cc[Added - diff]
• base/string_util.h[diff]
• base/sys_info_posix.cc[diff]
• base/system_monitor_unittest.cc[diff]
• base/third_party/icu/README[Added - diff]
• base/third_party/icu/icu_utf.cc[Added - diff]
• base/third_party/icu/icu_utf.h[Added - diff]
• base/trace_event.cc[diff]
• base/utf_string_conversions.cc[Added - diff]
• base/utf_string_conversions.h[Added - diff]
• base/values.cc[diff]
• chrome/browser/download/download_manager_unittest.cc[diff]