Revert "Revert "move onto new factories for SkMatrix""

This reverts commit c80ee456adf664c4a62fa2ccaeaf157c723ed656.

fix: update flutter's gn file to add guard

Change-Id: Iac5171c8475d9a862d06255dab1c6f38f10de2f2
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/291361
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/src/utils/SkShadowUtils.cpp b/src/utils/SkShadowUtils.cpp
index 869997f..ade48e3 100644
--- a/src/utils/SkShadowUtils.cpp
+++ b/src/utils/SkShadowUtils.cpp
@@ -594,8 +594,7 @@
             SkAutoDeviceTransformRestore adr(
                     this,
                     hasPerspective ? SkMatrix::I()
-                                   : SkMatrix::Concat(this->localToDevice(),
-                                                      SkMatrix::MakeTrans(tx, ty)));
+                                   : this->localToDevice() * SkMatrix::Translate(tx, ty));
             this->drawVertices(vertices, mode, paint);
         }
     };