From Xojo Documentation

Read-Only Property (As Boolean )
BooleanValue = aWebAnimator.XRotationSupported

New in 2010r4

Supported for all project types and targets.

Returns True if x-axis rotation animation is supported by the browser. If False, then the RotateX method does nothing.

Sample Code

Call RotateX if supported by the browser:

If Animator1.XRotationSupported Then
Animator1.RotateX(ImageView1, 180, 0.5)
End If