Update the computed transform when the reference box changes

When the object bounding box (for 'fill-box') or the viewport (for
'view-box') changes, we need to update the transform as well.
Add a bool to LayoutSVGShape to track if the transform depends on the
reference box, to make checking this quicker.

Bug: 595829
Change-Id: Ie7429553e78b08f7a574b1e7beae30c738250078
Reviewed-on: https://chromium-review.googlesource.com/796271
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Cr-Commit-Position: refs/heads/master@{#520259}
3 files changed