Fix for texture allocation failure in 'preAbandonGpuContext' mode

src/gpu/SkGpuDevice.cpp

Index: src/gpu/SkGpuDevice.cpp
diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index 3434671d6add50f4532dcf25ba4fe0545edc01b7..3ff2f2085c600baa278c79d32032a8e636dc0031 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -1733,6 +1733,9 @@ bool SkGpuDevice::filterImage(const SkImageFilter* filter, const SkBitmap& src,
     // We assume here that the filter will not attempt to tile the src. Otherwise, this cache lookup
     // must be pushed upstack.
     AutoBitmapTexture abt(fContext, src, NULL, &texture);
+    if (!texture) {
+        return false;
+    }
 
     return this->filterTexture(fContext, texture, src.width(), src.height(),
                                filter, ctx, result, offset);