Removing redundant tests from fast/workers.

Removing redundant tests created by this cl:
https://chromium-review.googlesource.com/c/chromium/src/+/1412827

These tests have equivalents in external/wpt/workers.

Bug: 795636
Change-Id: I274cd39d51d71ace07e630da2cec59c1d10e9a92
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1529747
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Commit-Queue: Katie Dillon <kdillon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#641994}
12 files changed