Revert "[Perf waterfall] Schedule weblayer perf tests."

This reverts commit b830d99b9641216aeb8199f3bc5f9f13832fc9c8.

Reason for revert: https://chromium-review.googlesource.com/c/chromium/tools/build/+/1924552 needed to be reverted 

Original change's description:
> [Perf waterfall] Schedule weblayer perf tests.
> 
> Two related tasks were accomplished here:
> 1. Make a new builder android-pixel2_weblayer-perf and tell it to run
> performance_weblayer_test_suite.
> 2. Configure a shard map for android-pixel2_weblayer-perf that tells
> it which benchmarks to run.
> 
> Bug: 1022823
> Change-Id: I753e40088b700520bcb15f0d97f605a262c471ee
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1918357
> Reviewed-by: John Budorick <jbudorick@chromium.org>
> Reviewed-by: John Chen <johnchen@chromium.org>
> Commit-Queue: Caleb Rouleau <crouleau@chromium.org>
> Auto-Submit: Caleb Rouleau <crouleau@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#716483}

TBR=jam@chromium.org,crouleau@chromium.org,johnchen@chromium.org,jbudorick@chromium.org

Change-Id: I6fdf911909cb310f61a1a4c6c32f977b6e618a06
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1022823, 1026245
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1925127
Reviewed-by: Caleb Rouleau <crouleau@chromium.org>
Commit-Queue: Caleb Rouleau <crouleau@chromium.org>
Cr-Commit-Position: refs/heads/master@{#716696}
8 files changed