touch_ScrollDirection test uses four gesture files that scroll. All scrolls
recorded should be unaccelerated and done in a single motion (i.e. do not
lift fingers and continue to scroll). Having the scroll stop in the middle of
the test would break the test. The gesture files for each device recorded are:

<DEVICE NAME>_touchpad_Touch ID_scroll-down  - Two finger scroll on touchpad in downward direction.
<DEVICE NAME>_touchpad_Touch ID_scroll-right - Two finger scroll on touchpad in right direction.
<DEVICE NAME>_touchpad_Touch ID_scroll-left  - Two finger scroll on touchpad in left direction.
<DEVICE NAME>_touchpad_Touch ID_scroll-up    - Two finger scroll on touchpad in upward direction.

To position the cursor on center of page, center_cursor gesture file is used:

center_cursor - Use mouse to move the mouse pointer to center of the screen.
                We do not know where the pointer would show up at the start
                of this test so must ensure that any starting cursor position
                will result in a centered cursor. Move the cursor well into a
                corner of the screen, and then move the cursor back to center of
                the test page. Do not pause the movement until pointer is at
                the center of page.