Use factory methods for Skia effects in unit tests.

cc/trees/damage_tracker_unittest.cc

Index: cc/trees/damage_tracker_unittest.cc
diff --git a/cc/trees/damage_tracker_unittest.cc b/cc/trees/damage_tracker_unittest.cc
index 51a6137ad5836da99f6dbcef2d9c7302e2e4bf40..d86b340176f58e967ec9e0d3346c15b28beed634 100644
--- a/cc/trees/damage_tracker_unittest.cc
+++ b/cc/trees/damage_tracker_unittest.cc
@@ -540,9 +540,8 @@ TEST_F(DamageTrackerTest, VerifyDamageForImageFilter) {
   // Allow us to set damage on child too.
   child->SetDrawsContent(true);
 
-  skia::RefPtr<SkImageFilter> filter =
-          skia::AdoptRef(new SkBlurImageFilter(SkIntToScalar(2),
-                                               SkIntToScalar(2)));
+  skia::RefPtr<SkImageFilter> filter = skia::AdoptRef(
+      SkBlurImageFilter::Create(SkIntToScalar(2), SkIntToScalar(2)));
   FilterOperations filters;
   filters.Append(FilterOperation::CreateReferenceFilter(filter));