Handle nullptr from asTextureRef

src/image/SkImage.cpp

Index: src/image/SkImage.cpp
diff --git a/src/image/SkImage.cpp b/src/image/SkImage.cpp
index f976242eca0086c037c2f4f333136ea3a69199ad..3487b7d92748596ecc9d0bdfaf80402b5e993a27 100644
--- a/src/image/SkImage.cpp
+++ b/src/image/SkImage.cpp
@@ -351,6 +351,9 @@ sk_sp<SkImage> SkImage::makeWithFilter(const SkImageFilter* filter, const SkIRec
     if (result->isTextureBacked()) {
         GrContext* context = result->getContext();
         sk_sp<GrTexture> texture = result->asTextureRef(context);
+        if (!texture) {
+            return nullptr;
+        }
         fullSize = SkIRect::MakeWH(texture->width(), texture->height());
     }
 #endif