add drawPicture variant that takes a matrix and paint

will need some staging strategy, since chrome and blink have overrides of onDrawPicture

R=robertphillips@google.com, fmalita@google.com, bsalomon@google.com, mtklein@google.com

Author: reed@google.com

Review URL: https://codereview.chromium.org/448793004
diff --git a/include/gpu/SkGpuDevice.h b/include/gpu/SkGpuDevice.h
index 5ff26f6..b856d66 100644
--- a/include/gpu/SkGpuDevice.h
+++ b/include/gpu/SkGpuDevice.h
@@ -143,7 +143,8 @@
     /**  PRIVATE / EXPERIMENTAL -- do not call */
     virtual void EXPERIMENTAL_optimize(const SkPicture* picture) SK_OVERRIDE;
     /**  PRIVATE / EXPERIMENTAL -- do not call */
-    virtual bool EXPERIMENTAL_drawPicture(SkCanvas* canvas, const SkPicture* picture) SK_OVERRIDE;
+    virtual bool EXPERIMENTAL_drawPicture(SkCanvas* canvas, const SkPicture* picture,
+                                          const SkMatrix*, const SkPaint*) SK_OVERRIDE;
 
 private:
     GrContext*      fContext;