GitLab

- Add methods to CrashFileManager to list files with certain upload
  states: forced uploads, skipped upload or ready for upload but not
  forced.
- These methods match the suffix of file names which is used to record
  minidump file upload state.

- Add UnuploadedFilesStateLoader which get the upload state of
  Unuploaded crash files. It uses the newly added methods in
  CrashFileManager.
- This info should be combined with info collected from other logs
  then used in WebView crash UI.

Bug: 964392
Change-Id: Id31013de2dd45235a4a1147591ef3636389b9e89
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1617766
Commit-Queue: Scott Violet <sky@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Tobias Sargeant <tobiasjs@chromium.org>
Auto-Submit: Hazem Ashmawy <hazems@chromium.org>
Cr-Commit-Position: refs/heads/master@{#683693}