This reverts commit 3edda8d185.
Reason for revert: Breaks rebase-update; crbug.com/324358728
Original change's description:
> Update gclient to use git config caching
>
> This change updates all the modules used by gclient to use `scm.GIT` for git config calls over directly invoking the subprocess.
>
> This change currently doesn't modify git_cache since the config reads and writes within it are done on bare repository. A follow-up CL will update git_cache.
>
> A follow-up CL will also update git_cl and git_map_branches since they have shown performance improvements too: https://crrev.com/c/4697786.
>
> Benchmarking
> ============
> With chromium/src as the baseline super project, this change reduces about 380 git config calls out of 507 total calls on cache hits during no-op. The below numbers are benchmarked with `update_depot_tools` turned off.
>
> Windows Benchmark
> =================
> Baseline (gpaste/6360045736951808): ~1min 12 sec.
> With Caching (gpaste/6480065209040896): ~1min 3sec.
> ~12.5% decrease in gclient sync noop runtime.
>
> Linux Benchmark
> ===============
> Baseline (gpaste/4730436763254784): ~3.739 sec.
> With Caching (gpaste/4849870978940928): ~3.534 sec.
> ~5.5% decrease in gclient sync noop runtime.
>
> Bug: 1501984
> Change-Id: Ib48df2d26a0c742a9b555a1e2ed6366221c7db17
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/5252498
> Commit-Queue: Aravind Vasudevan <aravindvasudev@google.com>
> Reviewed-by: Josip Sokcevic <sokcevic@chromium.org>
Bug: 1501984
Change-Id: I4a603238d9ed43edafc8e574493800670520a1d9
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/5279198
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Aravind Vasudevan <aravindvasudev@google.com>