Revert "BlobUrlLoader: Instrument for bug 882661."

This reverts commit 4ff885a19e44b128bc9151a93289ce61a313295c.

Reason for revert: CHECK not reached. The URLLoader to blame was the
WebRequestProxyingURLLoader.

Original change's description:
> BlobUrlLoader: Instrument for bug 882661.
> 
> In bug 882661: one mojo::URLLoader is sending OnStartLoadingResponseBody
> without sending OnReceiveResponse before.
> 
> Add instrumentation to check this never happen with this class.
> 
> Bug: 882661
> Change-Id: Ia9df5debbc03f0a5296c64edbcf6d975806bc021
> Reviewed-on: https://chromium-review.googlesource.com/c/1304435
> Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
> Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#605181}

TBR=kinuko@chromium.org,mek@chromium.org,arthursonzogni@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 882661
Change-Id: I16e8a5709f34d6909445c9cb0f674f07702ff594
Reviewed-on: https://chromium-review.googlesource.com/c/1329782
Reviewed-by: Arthur Sonzogni <arthursonzogni@chromium.org>
Reviewed-by: Marijn Kruisselbrink <mek@chromium.org>
Commit-Queue: Arthur Sonzogni <arthursonzogni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606897}
2 files changed