Revert "x11: Fix a few touch-event related issues:"

This reverts Chromium commit f8a9520395d7a1e478e6f134d1bb016f45087d00.

[Tizen] Re-enable pinch zoom in Tizen 2.X.

Chromium had hack to emulate multi touch using XIButton events. However,
unfortunately, above commit dropped the hack, because Chromium officially
supports XInput 2.2 or above.

Tizen 2.X has used the hack because Tizen 2.X does not support XInput2.2 touch
event.
In detail,
1) Tizen 2.1 supports XInput2.1.
2) Tizen 2.2.1 supports XInput2.2, but uses XI_Button event instead of XI_Touch
event.

So this PR reverts the commit to support multi touch to Tizen 2.X. If we bump
up to Tizen 3.0, this commit can be removed.

BUG=https://crosswalk-project.org/jira/browse/XWALK-445