Remove usages of touchEventEmulationEnabled setting from tests.

This setting is going away along with touch emulation tests. The only
clients left are some layout tests.

BUG=none

Review URL: https://codereview.chromium.org/228523002

git-svn-id: svn://svn.chromium.org/blink/trunk@171263 bbb929c8-8fbe-4397-9dbb-9b2b20218538