GitLab

In W3C mode for ChromeDriver, the response format changed. Code
was modified to extract sessionId from the new response format.

Bug: chromedriver:3076
Change-Id: Iaf749fa480fcbe541d8b520357c4344c79241dc0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1746787Reviewed-by: John Chen <johnchen@chromium.org>
Commit-Queue: Tricia Crichton <triciac@chromium.org>
Cr-Commit-Position: refs/heads/master@{#686452}