Add a feature flag for not exposing key board event to web

Chrome does not expose key events to pages for spatnav. This is to prevent
pages from accidentally interfering with the built-in behavior.

Bug: 920818
Change-Id: I9476b4b5b5d8aa2ff53c07c64ce50c2a9a7812b1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1500599
Commit-Queue: Jianpeng Chao <[email protected]>
Reviewed-by: Daniel Cheng <[email protected]>
Reviewed-by: Philip Rogers <[email protected]>
Reviewed-by: Avi Drissman <[email protected]>
Reviewed-by: David Bokan <[email protected]>
Cr-Commit-Position: refs/heads/master@{#644176}
13 files changed