Temporarily disable support of mipmapped flattened YUVA image

Bug:
Change-Id: Ifea233b68c2e4c41abe68cf7654054da02d12d38
Reviewed-on: https://skia-review.googlesource.com/c/168273
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
diff --git a/src/gpu/GrImageTextureMaker.cpp b/src/gpu/GrImageTextureMaker.cpp
index cf74545..70cbe64 100644
--- a/src/gpu/GrImageTextureMaker.cpp
+++ b/src/gpu/GrImageTextureMaker.cpp
@@ -54,7 +54,16 @@
 
 sk_sp<GrTextureProxy> GrYUVAImageTextureMaker::refOriginalTextureProxy(bool willBeMipped,
                                                                    AllowedTexGenType onlyIfFast) {
-    return (AllowedTexGenType::kCheap == onlyIfFast) ? nullptr : fImage->asTextureProxyRef();
+    if (AllowedTexGenType::kCheap == onlyIfFast) {
+        return nullptr;
+    }
+
+    auto proxy = fImage->asTextureProxyRef();
+    if (willBeMipped && proxy && GrMipMapped::kNo == proxy->mipMapped()) {
+        return nullptr;
+    }
+
+    return proxy;
 }
 
 void GrYUVAImageTextureMaker::makeCopyKey(const CopyParams& stretch, GrUniqueKey* paramsCopyKey) {