Revert of Instrumented libraries: Remove dependence on GYP_DEFINES (patchset #2 id:60001 of https://codereview.chromium.org/2775913002/ )

Reason for revert:
Reverting now that all of the third_party changes have been reverted

Original issue's description:
> Instrumented libraries: Remove dependence on GYP_DEFINES
>
> This CL ports download_binaries.py and unpack_binaries.py from using
> GYP_DEFINES to gn args.  Previously, there was a gotcha step where you
> had to run 'gclient sync' with the right GYP_DEFINES to actually download
> the prebuilt instrumented libraries.  This CL removes that step.
>
> CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_msan_rel_ng;master.tryserver.chromium.linux:linux_chromium_chromeos_msan_rel_ng
> R=eugenis@chromium.org
> BUG=705072
>
> Review-Url: https://codereview.chromium.org/2775913002
> Cr-Commit-Position: refs/heads/master@{#459630}
> Committed: https://chromium.googlesource.com/chromium/src/+/5adb8c047852670be6c9d42114f3a17d44b6c56e

TBR=eugenis@chromium.org,dpranke@chromium.org,machenbach@chromium.org,thomasanderson@google.com
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=705072

Review-Url: https://codereview.chromium.org/2792343003
Cr-Original-Commit-Position: refs/heads/master@{#461871}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: aa441f50eecca13f2d3490a89705cb00cc0d5920
3 files changed
tree: d7e5c3a42b069b4e4e10c6ceef0cd0ce196d08c7
  1. BUILD.gn
  2. OWNERS
  3. README.chromium
  4. binaries/
  5. blacklists/
  6. patches/
  7. scripts/