Convert drawPaint to drawRRect in simple cases

include/gpu/GrClip.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrClip_DEFINED
 #define GrClip_DEFINED
 
@@ skipping 15 matching lines @@
         return this->quickContains(rrect.getBounds());
     }
     virtual void getConservativeBounds(int width, int height, SkIRect* devResult,
                                        bool* isIntersectionOfRects = nullptr) const = 0;
     virtual bool apply(GrContext*, GrDrawContext*, bool useHWAA, bool hasUserStencilSettings,
                        GrAppliedClip* out) const = 0;
 
     virtual ~GrClip() {}
 
     /**
+     * This method quickly and conservatively determines whether the entire clip is equivalent to
+     * intersection with a rrect.
+     *
+     * @param rtBounds The bounds of the render target that the clip will be applied to.
+     * @param rrect    If return is true rrect will contain the rrect equivalent to the clip.
+     * @param aa       If return is true aa will indicate whether the rrect clip is antialiased.
+     * @return true if the clip is equivalent to a single rrect, false otherwise.
+     */
+    virtual bool isRRect(const SkRect& rtBounds, SkRRect* rrect, bool* aa) const = 0;
+
+    /**
      * This is the maximum distance that a draw may extend beyond a clip's boundary and still count
      * count as "on the other side". We leave some slack because floating point rounding error is
      * likely to blame. The rationale for 1e-3 is that in the coverage case (and barring unexpected
      * rounding), as long as coverage stays within 0.5 * 1/256 of its intended value it shouldn't
      * have any effect on the final pixel values.
      */
     constexpr static SkScalar kBoundsTolerance = 1e-3f;
 
     /**
      * Returns true if the given query bounds count as entirely inside the clip.
@@ skipping 69 matching lines @@
     void getConservativeBounds(int width, int height, SkIRect* devResult,
                                bool* isIntersectionOfRects) const final {
         devResult->setXYWH(0, 0, width, height);
         if (isIntersectionOfRects) {
             *isIntersectionOfRects = true;
         }
     }
     bool apply(GrContext*, GrDrawContext*, bool, bool, GrAppliedClip*) const final {
         return true;
     }
+    bool isRRect(const SkRect&, SkRRect*, bool*) const override { return false; };
 };
 
 #endif