SkTCopyOnFirstWrite-based SkPaintFilterCanvas API

include/utils/SkPaintFilterCanvas.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkPaintFilterCanvas_DEFINED
 #define SkPaintFilterCanvas_DEFINED
 
@@ skipping 31 matching lines @@
         kTextBlob_Type,
         kVertices_Type,
         kPatch_Type,
 
         kTypeCount
     };
 
 protected:
     /**
      *  Called with the paint that will be used to draw the specified type.
-     *
-     *  Upon return, if filteredPaint is initialized it will replace the original paint
-     *  for the current draw.  Note that that implementation is responsible for
-     *  initializing *filteredPaint (e.g. via set(*paint)).
+     *  The implementation may modify the paint as they wish (using SkTCopyOnFirstWrite::writable).
      *
      *  The result bool is used to determine whether the draw op is to be
-     *  executed (true) or skipped (false).  When the draw is skipped, filteredPaint is
-     *  ignored.
+     *  executed (true) or skipped (false).
      *
      *  Note: The base implementation calls onFilter() for top-level/explicit paints only.
      *        To also filter encapsulated paints (e.g. SkPicture, SkTextBlob), clients may need to
      *        override the relevant methods (i.e. drawPicture, drawTextBlob).
      */
-    virtual bool onFilter(const SkPaint* paint, Type type, SkTLazy<SkPaint>* filteredPaint) const {
-        if (paint) {
-            this->onFilterPaint(filteredPaint->set(*paint), type);
+    virtual bool onFilter(SkTCopyOnFirstWrite<SkPaint>* paint, Type type) const {
+        if (*paint) {
+            this->onFilterPaint(paint->writable(), type);
         }
         return true;
     }
 
     // DEPRECATED - do not use
     virtual void onFilterPaint(SkPaint*, Type) const { }
 
     void onDrawPaint(const SkPaint&) override;
     void onDrawPoints(PointMode, size_t count, const SkPoint pts[], const SkPaint&) override;
     void onDrawRect(const SkRect&, const SkPaint&) override;
@@ skipping 32 matching lines @@
     void onDrawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y,
                         const SkPaint& paint) override;
 
 private:
     class AutoPaintFilter;
 
     typedef SkNWayCanvas INHERITED;
 };
 
 #endif