Allow Text node in elementsFromPoint if descendant of SVG text content

When hit-testing, SVG text content nodes will use their Text node
descendants as the inner-most/hit node, and hit-testing will not be
performed in any of the background phases. Thus we need to selectively
allow Text node which has an SVG text content element as their parent.

Bug: 842504
Change-Id: Ie282d5e9a66880f3f0d5e319b249f5f41db9e9db
Reviewed-on: https://chromium-review.googlesource.com/1059753
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561238}
2 files changed