VR: Restore color animation on URL bar

The URL bar color should animate when switching to and from incognito
mode.

BUG=836236
R=asimjour

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_vr
Change-Id: I4bd0eda60d5bc0852dfc739e5fd20c5b6c970291
Reviewed-on: https://chromium-review.googlesource.com/1025955Reviewed-by: Amirhossein Simjour <asimjour@chromium.org>
Commit-Queue: Christopher Grant <cjgrant@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553184}

chrome/browser/vr/ui_scene_creator.cc

@@ -1911,6 +1911,7 @@ void UiSceneCreator::CreateUrlBar() {
   url_bar->SetRotate(1, 0, 0, kUrlBarRotationRad);
   url_bar->set_bounds_contain_children(true);
   url_bar->set_corner_radius(kUrlBarHeightDMM / 2);
+  url_bar->SetTransitionedProperties({FOREGROUND_COLOR, BACKGROUND_COLOR});
   VR_BIND_VISIBILITY(url_bar, !model->fullscreen_enabled());
   VR_BIND_COLOR(model_, url_bar.get(), &ColorScheme::url_bar_background,
                 &Rect::SetColor);