Remove more LoFi code

- PLM observer
- Histograms
- Context Menu
- DRP Server LoFi Triggering
- ServerLoFi Blink code

Bug: 944286
Change-Id: I05de571209c85d6fb24dd47074b26b5ed171e190
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1652012
Commit-Queue: Robert Ogden <[email protected]>
Reviewed-by: Ted Choc <[email protected]>
Reviewed-by: Ryan Sturm <[email protected]>
Reviewed-by: Tarun Bansal <[email protected]>
Cr-Commit-Position: refs/heads/master@{#670344}
55 files changed