Animometer's fragment shaders remains unported because it isn't clear
how to use modf in WGSL.
Bug: dawn:572
Change-Id: I29aa0ee657b813e7308f0300addd1d5795bfc16d
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/33821
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>