call drawRect to try GrAARectRenderer if the path is a rect

experimental/PdfViewer/SkNulCanvas.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkNulCanvas_DEFINED
 #define SkNulCanvas_DEFINED
 
@@ skipping 37 matching lines @@
                            bool doAntiAlias = false) {return true;}
     virtual bool clipPath(const SkPath& path,
                           SkRegion::Op op = SkRegion::kIntersect_Op,
                           bool doAntiAlias = false) {return true;}
     virtual bool clipRegion(const SkRegion& deviceRgn,
                             SkRegion::Op op = SkRegion::kIntersect_Op) {return true;}
     virtual void clear(SkColor) {}
     virtual void drawPaint(const SkPaint& paint) {}
     virtual void drawPoints(PointMode mode, size_t count, const SkPoint pts[],
                             const SkPaint& paint) {}
-    virtual void drawRect(const SkRect& rect, const SkPaint& paint) {}
     virtual void drawOval(const SkRect& oval, const SkPaint&) {}
     virtual void drawRRect(const SkRRect& rrect, const SkPaint& paint) {}
-    virtual void drawPath(const SkPath& path, const SkPaint& paint) {}
     virtual void drawBitmap(const SkBitmap& bitmap, SkScalar left, SkScalar top,
                             const SkPaint* paint = NULL) {}
     virtual void drawBitmapRectToRect(const SkBitmap& bitmap, const SkRect* src,
                                       const SkRect& dst,
                                       const SkPaint* paint,
                                       DrawBitmapRectFlags flags) {}
     virtual void drawBitmapMatrix(const SkBitmap& bitmap, const SkMatrix& m,
                                   const SkPaint* paint = NULL) {}
     virtual void drawBitmapNine(const SkBitmap& bitmap, const SkIRect& center,
                                 const SkRect& dst, const SkPaint* paint = NULL) {}
@@ skipping 16 matching lines @@
                               const uint16_t indices[], int indexCount,
                               const SkPaint& paint) {}
     virtual void drawData(const void* data, size_t length) {}
     virtual void beginCommentGroup(const char* description) {}
     virtual void addComment(const char* kywd, const char* value) {}
     virtual void endCommentGroup() {}
     virtual SkBounder* setBounder(SkBounder* bounder) {return NULL;}
     virtual SkDrawFilter* setDrawFilter(SkDrawFilter* filter) {return NULL;}
 
 protected:
+    virtual void onDrawRect(const SkRect& rect, const SkPaint& paint) {}
+    virtual void onDrawPath(const SkPath& path, const SkPaint& paint) {}
     virtual SkCanvas* canvasForDrawIter() {return NULL;}
     virtual SkBaseDevice* setDevice(SkBaseDevice* device) {return NULL;}
 
 private:
     typedef SkCanvas INHERITED;
 };
 
 #endif  // SkNulCanvas_DEFINED