GitLab

Children of elements with no size are offscreen still by virtue
of being clipped.

This fixes <br> tags (lineBreak) being labeled 'offscreen',
as well as any size (0, 0) element that is on the screen.

Bug: 773851
Change-Id: I3e2ed49d3b66b3eb3280f44fcf86315273cce485
Reviewed-on: https://chromium-review.googlesource.com/772900Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: Katie D <katie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#517558}