metrics: replace "Logging.*" with "Platform.*"

"Logging.*" is not a good name.
Also remove unused function ReportDailyUse().

BUG=chromium:508535
TEST=it compiles

Change-Id: I070bada4857abd80989ecc746adcbf1dcf6239a3
Reviewed-on: https://chromium-review.googlesource.com/284610


Tested-by: Luigi Semenzato <semenzato@chromium.org>
Reviewed-by: Sonny Rao <sonnyrao@chromium.org>
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Commit-Queue: Luigi Semenzato <semenzato@chromium.org>