expand gm to test GPU and CPU

Change-Id: I7d1c80f1b7dadc8535736385aa3adb935fa24293
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/271237
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/gm/runtimecolorfilter.cpp b/gm/runtimecolorfilter.cpp
index 35fb6ba..84a7bb3 100644
--- a/gm/runtimecolorfilter.cpp
+++ b/gm/runtimecolorfilter.cpp
@@ -31,7 +31,7 @@
     }
 )";
 
-DEF_SIMPLE_GPU_GM(runtimecolorfilter, context, rtc, canvas, 512, 256) {
+DEF_SIMPLE_GM(runtimecolorfilter, canvas, 512, 256) {
     auto img = GetResourceAsImage("images/mandrill_256.png");
     canvas->drawImage(img, 0, 0, nullptr);