Revert "Check for counter overflows when merging profraw files."

This reverts commit 677b08ef14cc79c5faf7052651c9d2a298301a5c.

Reason for revert: This seems to be messing with the code coverage builders.

Original change's description:
> Check for counter overflows when merging profraw files.
> 
> R=​sajjadm,liaoyuke
> 
> Bug: 1020404
> Change-Id: I28e27f40aebbc9743da1fa7cc42deb03f77cee13
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1894619
> Reviewed-by: Yuke Liao <liaoyuke@chromium.org>
> Commit-Queue: Roberto Carrillo <robertocn@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#712266}

TBR=robertocn@chromium.org,liaoyuke@chromium.org,sajjadm@chromium.org

Change-Id: Ib7e3c45ac146977c13e133be2200433778558741
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1020404
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1899546
Reviewed-by: Roberto Carrillo <robertocn@chromium.org>
Commit-Queue: Roberto Carrillo <robertocn@chromium.org>
Cr-Commit-Position: refs/heads/master@{#712494}
3 files changed