Flutter does use legacy image.makeShader()

Bug: skia:7650
Change-Id: I779944e25b8ca241a60f2c2880c95460b5f20545
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/374596
Reviewed-by: Mike Reed <reed@google.com>
diff --git a/gn/flutter_defines.gni b/gn/flutter_defines.gni
index c128c88..2c7e175 100644
--- a/gn/flutter_defines.gni
+++ b/gn/flutter_defines.gni
@@ -15,7 +15,6 @@
   "SK_PARAGRAPH_LIBTXT_SPACES_RESOLUTION",
 
   # Staging
-  "SK_SUPPORT_LEGACY_IMPLICIT_FILTERQUALITY",
 
   # Fast low-precision software rendering isn't a priority for Flutter.
   "SK_DISABLE_LEGACY_SHADERCONTEXT",