Bug 1442915 - Don't use shadow visible region in DefaultComputeEffectiveTransforms since it might not be computed yet. r=mstange

gfx/layers/Layers.cpp

@@ -1314,7 +1314,7 @@ ContainerLayer::DefaultComputeEffectiveTransforms(const Matrix4x4& aTransformToS
     // transform while 2D is expected.
     idealTransform.ProjectTo2D();
   }
-  mUseIntermediateSurface = useIntermediateSurface && !GetLocalVisibleRegion().IsEmpty();
+  mUseIntermediateSurface = useIntermediateSurface;
   if (useIntermediateSurface) {
     ComputeEffectiveTransformsForChildren(Matrix4x4::From2D(residual));
   } else {