Revert of Add CHECKs to investigate ResourceThrottle crash. (patchset #11 id:280001 of https://codereview.chromium.org/2271403002/ )

Reason for revert:
Figured out the issue, these are no longer needed.

Original issue's description:
> Add CHECKs to investigate ResourceThrottle crash.
>
> BUG=640545
>
> Committed: https://crrev.com/25d0501e6e9cf23cda9ea26a1b380dbbb4db0ba3
> Cr-Commit-Position: refs/heads/master@{#414899}

TBR=csharrison@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=640545

Review-Url: https://codereview.chromium.org/2357173003
Cr-Commit-Position: refs/heads/master@{#420151}
2 files changed