GitLab

This patch adds a cache of the SVG marker transform, similar to the pattern
used in LayoutSVGViewportContainer. This should be a small perf win because
we no longer re-calculate the transform when painting each marker instance.
With this new cache logic, invalidation logic has been added which includes
a fix for paint property under-invalidation (marker-viewBox-changes.svg).

BUG=645667,600618

Review-Url: https://codereview.chromium.org/2565943002
Cr-Commit-Position: refs/heads/master@{#437993}