Use the authoritative upstream source for Breakpad, move to third_party

Relands 5b41612edd88, reverted at 0b24f77010b8.

Breakpad was being synced from a read-only mirror of a subdirectory
rather than the authoritative upstream source. This encouraged Chrome
developers to send patches against the read-only mirror. Those patches
couldn’t be committed and needed to be duplicated in the correct
repository. Once, a patch against the read-only mirror accidentally was
committed, and it broke mirroring.

This odd setup existed from the time of the git migration. Prior to
that, Breakpad was hosted in Subversion, and Chrome incidentally pulled
Breakpad’s src subdirectory rather than the entire trunk directory.
Because it wasn‘t easy to do the same thing with git, the read-only
mirror of src was created to avoid having to change lots of paths in
Chrome. But now I’m changing the paths.

This also moves Breakpad from the top-level breakpad directory in Chrome
to third_party/breakpad. It should have been there all along, but
Breakpad was one of the earliest dependencies added to Chrome, and at
that time, there was no firm policy on where to put Google-originated
external code.

Bug: 766917
Change-Id: Ia52d459d6ea8dee4157b42a265f3eeb8b15ddc1f
TBR: thestig@chromium.org, pinkerton@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/681838
Commit-Queue: Mark Mentovai <mark@chromium.org>
Reviewed-by: Mark Mentovai <mark@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#504087}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: ebb9ddd665a0a163d9e8a31ff2bf8104c858d67f
10 files changed
tree: 4b825dc642cb6eb9a060e54bf8d69288fbee4904

This tree is empty.