[chromedriver] When doing linux32 tests, wait for chromium snapshot builds instead of blink builds.

BUG=
NOTRY=True
R=stgao@chromium.org

Review URL: https://codereview.chromium.org/326303002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@276280 0039d316-1c4b-4281-b951-d872f2087c98
[chromedriver] Fix waiting and downloading snapshot builds.

TBR=samuong

Review URL: https://codereview.chromium.org/323383004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@276431 0039d316-1c4b-4281-b951-d872f2087c98