Add test for "fully overlapping" radial gradient case

This adds a test for the case where the start and end circles of a
radial gradient fully overlap (while having non-zero radii).

Bug: 933413
Change-Id: Id059cb607f6fc137111d2306dd9c9eef1f55b6bc
Reviewed-on: https://chromium-review.googlesource.com/c/1483023
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>
Auto-Submit: Fredrik Söderquist <fs@opera.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
Cr-Commit-Position: refs/heads/master@{#634711}
1 file changed