Remove explicit -Wextra-semi, -Winconsistent-missing-override flags.
Remove explicit -Wextra-semi, -Winconsistent-missing-override flags.

They're  enabled via the chromium_code config already these days.
No intended behavior change.

Bug: chromium:926235,chromium:428099

Change-Id: I6927d6e3ec85f40454da61969d7a22dfabef1bde
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1564781
Reviewed-by: Jamie Madill <7e492b4f1c8458024932de3ba475cbf015424c30@chromium.org>
Commit-Queue: Nico Weber <c0f02d98506190746d1cdcb01be0f37b51e27077@chromium.org>

ppy/angle,ppy/angle,ppy/angle,ppy/angle