GitLab

The WarmupURLFetcherCallback histogram could get recorded more number of
times depending on retries.

Bug: 969795
Change-Id: I13b65dfe4a0fd7a70047f912ff960c201c2eb719
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1641811Reviewed-by: Robert Ogden <robertogden@chromium.org>
Commit-Queue: rajendrant <rajendrant@chromium.org>
Cr-Commit-Position: refs/heads/master@{#665816}