Fixing a few tests for user_prompts in ChromeDriver

Bug: 929418
Change-Id: If4d576954c873853c7c3bef622a47ef9079f06b3
Reviewed-on: https://chromium-review.googlesource.com/c/1461311
Reviewed-by: John Chen <johnchen@chromium.org>
Commit-Queue: John Jansen <johnjan@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#630845}
1 file changed