Update display_list_image_filter_unittests to be permit Skia roll (#37327)

* Update display_list_image_filter_unittests to be permit Skia roll

https://skia-review.googlesource.com/c/skia/+/571798 had to be reverted because it causes DisplayListImageFilter.LocalImageFilterBounds to fail. With SkMatrixTransformImageFilter (returned by SkImageFilters::MatrixTransform) supporting complex matrices, makeWithLocalMatrix(rotation) will no longer return null.

This is at odds with the behavior of DlImageFilter's implementation which tries to mimic the existing behavior of image filters. This relaxes the test case so that Skia can improve its implementation without breaking Flutter's tests. Flutter can then update DlImageFilter to match out-of-band.

* Update comment to reference flutter issue.

Author: lhkbob

display_list/display_list_image_filter_unittests.cc

@@ -810,8 +810,11 @@ TEST(DisplayListImageFilter, LocalImageFilterBounds) {
         auto sk_local_filter = sk_filters[i]->makeWithLocalMatrix(m);
         auto dl_local_filter = dl_filters[i]->makeWithLocalMatrix(m);
         if (!sk_local_filter || !dl_local_filter) {
-          ASSERT_TRUE(!sk_local_filter);
-          ASSERT_TRUE(!dl_local_filter);
+          // Temporarily relax the equivalence testing to allow Skia to expand
+          // their behavior. Once the Skia fixes are rolled in, the
+          // DlImageFilter should adapt  to the new rules.
+          // See https://github.com/flutter/flutter/issues/114723
+          ASSERT_TRUE(sk_local_filter || !dl_local_filter);
           continue;
         }
         {