Add overloaded GetProvidedFileSystemInfoList function.

This change adds an overloaded GetProvidedFileSystemInfoList() method
that takes a ProviderId as a parameter, and returns a vector containing
only FileSystemInfo entries for a specific Provider.

This change also modifies the FileSystemProvider API to use this new
function to reduce code duplication.

Bug: chromium:757625
Change-Id: I5426f6768f12a3347aa8b196d2c1804b4f1ed01d
Reviewed-on: https://chromium-review.googlesource.com/986943
Commit-Queue: Bailey Berro <baileyberro@chromium.org>
Reviewed-by: Naoki Fukino <fukino@chromium.org>
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548134}
3 files changed