implement drawAtlas natively on gpu-device

src/gpu/SkGpuDevice.h

Index: src/gpu/SkGpuDevice.h
diff --git a/src/gpu/SkGpuDevice.h b/src/gpu/SkGpuDevice.h
index 9fa756c29a2bfb855720081f0f845c07cb0df06d..86507657cd32b9182945d036eac191e6b106b0a0 100644
--- a/src/gpu/SkGpuDevice.h
+++ b/src/gpu/SkGpuDevice.h
@@ -111,6 +111,8 @@ public:
                               const SkColor colors[], SkXfermode* xmode,
                               const uint16_t indices[], int indexCount,
                               const SkPaint&) override;
+    void drawAtlas(const SkDraw&, const SkImage* atlas, const SkRSXform[], const SkRect[],
+                       const SkColor[], int count, SkXfermode::Mode, const SkPaint&) override;
     virtual void drawDevice(const SkDraw&, SkBaseDevice*, int x, int y,
                             const SkPaint&) override;
     void drawImage(const SkDraw&, const SkImage*, SkScalar x, SkScalar y, const SkPaint&) override;