This patch ensures that we check ShouldMaintainPreLevel() before attempting
to modify or read mPreLevel in order to avoid wasting time to compute
mPreLevel for elements without frames needlessly. Computing this value for
such elements can incur expensive style calculations.
This patch ensures that we check ShouldMaintainPreLevel() before attempting
to modify or read mPreLevel in order to avoid wasting time to compute
mPreLevel for elements without frames needlessly. Computing this value for
such elements can incur expensive style calculations.