Revert "Use the authoritative upstream source for Breakpad, move to third_party"

This reverts commit 5b41612edd88c44f77a686d85f0a8d7cc42ba56e.

Reason for revert: https://crbug.com/768262

Original change's description:
> Use the authoritative upstream source for Breakpad, move to third_party
> 
> 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
> TBR: pinkerton@chromium.org
> Change-Id: I860a3e92b0327898ba73b8678af258a9020eeaaf
> Reviewed-on: https://chromium-review.googlesource.com/677280
> Commit-Queue: Mark Mentovai <mark@chromium.org>
> Reviewed-by: Lei Zhang <thestig@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#503925}

TBR=thestig@chromium.org,pinkerton@chromium.org,mark@chromium.org
NOTREECHECKS=true
NOTRY=true

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 766917
Change-Id: Ie1590163f53cc7180506101aacf6cf39964e1457
Reviewed-on: https://chromium-review.googlesource.com/681014
Commit-Queue: Peter Conn <peconn@chromium.org>
Reviewed-by: Peter Conn <peconn@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#504018}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 0b24f77010b8af4dabc0d3cf37c2e864b29f5ed7
10 files changed