SVGAnimatedEnumeration initial values

This implements initial values for SVGAnimatedEnumeration properties.

Bug: 225807, 523685
Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I857dd5d6a52b2e3c4e866c2b589be3373449fc24
Reviewed-on: https://chromium-review.googlesource.com/1209683
Reviewed-by: Philip Rogers <pdr@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#589217}
5 files changed