Refactor .so name detection logic in minidump/linux_dumper.

This is a refactoring of the logic which determines the
module name and path for a given MappingInfo in minidump_writer.cc.
Such logic, which will be soon shared also with the upcoming
microdump_writer.cc, is simply being moved to linux_dumper.cc,
extracting a GetMappingEffectiveNameAndPath method.
No behavioral change is intended.

BUG=chromium:410294
R=thestig@chromium.org

Review URL: https://breakpad.appspot.com/7734002

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1392 4c0a9323-5329-0410-9bdc-e9ce6186880e
3 files changed