Temporary fix for --preAbandonGpuContext bug

src/core/SkSpecialImage.cpp

Index: src/core/SkSpecialImage.cpp
diff --git a/src/core/SkSpecialImage.cpp b/src/core/SkSpecialImage.cpp
index 2b371d6f747c06d97564d052625eb280e40052f5..b8eabc50bf577b4958b97675c997db323c27af4c 100644
--- a/src/core/SkSpecialImage.cpp
+++ b/src/core/SkSpecialImage.cpp
@@ -481,6 +481,10 @@ public:
     }
 
     sk_sp<SkSpecialSurface> onMakeSurface(const SkImageInfo& info) const override {
+        if (!fTexture->getContext()) {
+            return nullptr;
+        }
+
         GrSurfaceDesc desc = GrImageInfoToSurfaceDesc(info, *fTexture->getContext()->caps());
         desc.fFlags = kRenderTarget_GrSurfaceFlag;