[ChromeDriver] Allow Is Displayed in W3C mode

The Is Element Displayed command is not part of W3C spec, but is still
used by some APIs, and its functionality can be difficult to replicate
in those APIs. This CL re-enables this command in W3C mode to ease
transition to W3C mode.

(cherry picked from commit 7ad1eb9fcaa397da16033c6d612aee735e3dc5e4)

Bug: 973094, chromedriver:2943
Change-Id: I9a73e98d00e9d6965e7382793cc95b836b8933d6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1651514
Commit-Queue: John Chen <johnchen@chromium.org>
Commit-Queue: Caleb Rouleau <crouleau@chromium.org>
Auto-Submit: John Chen <johnchen@chromium.org>
Reviewed-by: Caleb Rouleau <crouleau@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#667804}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1656033
Reviewed-by: John Chen <johnchen@chromium.org>
Cr-Commit-Position: refs/branch-heads/3809@{#256}
Cr-Branched-From: d82dec1a818f378c464ba307ddd9c92133eac355-refs/heads/master@{#665002}
1 file changed