[ChromeDriver] Implement Get element property

Bug: chromedriver:1936
Change-Id: I9e385f3249226d886c49023126582a96e4687d82
Reviewed-on: https://chromium-review.googlesource.com/1231913
Reviewed-by: John Chen <[email protected]>
Commit-Queue: Tatiana Buldina <[email protected]>
Cr-Commit-Position: refs/heads/master@{#592285}
8 files changed