Add another dollop of sk_sp to SkSpecialImage and SkSpecialSurface

This is split out of https://codereview.chromium.org/1914883002/ (Refactor drawContext/RenderTarget creation)

GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1913743002

Review URL: https://codereview.chromium.org/1913743002
diff --git a/tests/ImageFilterTest.cpp b/tests/ImageFilterTest.cpp
index 952e5e5..54e9a60 100644
--- a/tests/ImageFilterTest.cpp
+++ b/tests/ImageFilterTest.cpp
@@ -368,6 +368,7 @@
 }
 
 static sk_sp<SkSpecialSurface> create_empty_special_surface(GrContext* context, int widthHeight) {
+#if SK_SUPPORT_GPU
     if (context) {
         GrSurfaceDesc desc;
         desc.fConfig = kSkia8888_GrPixelConfig;
@@ -375,7 +376,9 @@
         desc.fWidth  = widthHeight;
         desc.fHeight = widthHeight;
         return SkSpecialSurface::MakeRenderTarget(context, desc);
-    } else {
+    } else
+#endif
+    {
         const SkImageInfo info = SkImageInfo::MakeN32(widthHeight, widthHeight,
                                                       kOpaque_SkAlphaType);
         return SkSpecialSurface::MakeRaster(info);