remove dead methods now that we use specials exclusively for imagefilters

src/gpu/SkGpuDevice.h

Index: src/gpu/SkGpuDevice.h
diff --git a/src/gpu/SkGpuDevice.h b/src/gpu/SkGpuDevice.h
index b72e917a375bd1b9efa3c98b3f48b247bac95048..0b1e6a3cd9a32b2f92d63c2cb31be9655fdd7a78 100644
--- a/src/gpu/SkGpuDevice.h
+++ b/src/gpu/SkGpuDevice.h
@@ -269,9 +269,6 @@ private:
                                                   int sampleCount,
                                                   const SkSurfaceProps*);
 
-    void drawSpriteWithFilter(const SkDraw&, const SkBitmap&, int x, int y,
-                              const SkPaint&) override;
-
     friend class GrAtlasTextContext;
     friend class SkSurface_Gpu;      // for access to surfaceProps
     typedef SkBaseDevice INHERITED;