[chromedriver] Add 34 to test suite, remove 31 to test suite and remove 30

BUG=

Review URL: https://codereview.chromium.org/222613003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@263464 0039d316-1c4b-4281-b951-d872f2087c98
[chromedriver] Implement WebDriver.switchTo().parentFrame() command

BUG=chromedriver:760

Review URL: https://codereview.chromium.org/235003006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@263487 0039d316-1c4b-4281-b951-d872f2087c98
[chromedriver] Change CHROME_34_REVISION to one that is available in the continuous archive (251854); the previous revision (251904) was only available in the snapshots archive, but this is not where we download from for testing.

NOTRY=true

Review URL: https://codereview.chromium.org/225163007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@263548 0039d316-1c4b-4281-b951-d872f2087c98