[M45] SkPaintFilterCanvas should inherit the target canvas state

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
 
 #include "SkNWayCanvas.h"
 
 /** \class SkPaintFilterCanvas
 
     A utility proxy base class for implementing paint filters.
 */
 class SK_API SkPaintFilterCanvas : public SkNWayCanvas {
 public:
+    /**
+     * DEPRECATED: use the variant below.
+     */
     SkPaintFilterCanvas(int width, int height);
 
+    /**
+     * The new SkPaintFilterCanvas is configured for forwarding to the
+     * specified canvas.  Also copies the target canvas matrix and clip bounds.
+     */
+    SkPaintFilterCanvas(SkCanvas* canvas);
+
     enum Type {
         kPaint_Type,
         kPoint_Type,
         kBitmap_Type,
         kRect_Type,
         kRRect_Type,
         kDRRect_Type,
         kOval_Type,
         kPath_Type,
         kPicture_Type,
@@ skipping 53 matching lines @@
     void onDrawTextBlob(const SkTextBlob* blob, SkScalar x, SkScalar y,
                         const SkPaint& paint) override;
 
 private:
     class AutoPaintFilter;
 
     typedef SkNWayCanvas INHERITED;
 };
 
 #endif