Revert "Revert "Reland "Add particle GMs"""

This reverts commit ad8ce4dbb218852d0a717d77b144fe3371955b16.

Change-Id: I26077c56fa69e60a003359fa9da758bbfd6a3425
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/363777
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
diff --git a/gn/gm.gni b/gn/gm.gni
index d6cfe85..4d9fc8e 100644
--- a/gn/gm.gni
+++ b/gn/gm.gni
@@ -271,6 +271,7 @@
   "$_gm/overdrawcolorfilter.cpp",
   "$_gm/overstroke.cpp",
   "$_gm/p3.cpp",
+  "$_gm/particles.cpp",
   "$_gm/patch.cpp",
   "$_gm/path_stroke_with_zero_length.cpp",
   "$_gm/patharcto.cpp",