Mark a couple of UMA histograms as obsolete.
Mark a couple of UMA histograms as obsolete.

These are no longer logged. Not sure when they were removed.

BUG=none

Review URL: https://codereview.chromium.org/1876453002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#386293}

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