Update {virtual,override} to follow C++11 style in ui.

The Google style guide states that only one of {virtual,override,final} should be used for each declaration, since override implies virtual and final implies both virtual and override.

This patch was manually generated using a regex and a text editor.

BUG=417463

Review URL: https://codereview.chromium.org/1081103008

Cr-Commit-Position: refs/heads/master@{#326565}
8 files changed