Mash cleanup: Remove some more window and window frame related code.

TBR=tsepez@chromium.org

Bug: 958154
Change-Id: I21dadda1bd78fbd713eb3574edea7f2087100762
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1595982
Commit-Queue: Evan Stade <estade@chromium.org>
Auto-Submit: Evan Stade <estade@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#657429}
13 files changed