Revert of Revert "Serialization of SkPictureImageFilter"

include/effects/SkPictureImageFilter.h

 /*
  * Copyright 2013 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkPictureImageFilter_DEFINED
 #define SkPictureImageFilter_DEFINED
 
@@ skipping 10 matching lines @@
     /**
      *  Refs the passed-in picture. rect can be used to crop or expand the destination rect when
      *  the picture is drawn. (No scaling is implied by the dest rect; only the CTM is applied.)
      */
     SkPictureImageFilter(SkPicture* picture, const SkRect& rect);
 
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkPictureImageFilter)
 
 protected:
     virtual ~SkPictureImageFilter();
-    explicit SkPictureImageFilter(SkReadBuffer& buffer);
+    /*  Constructs an SkPictureImageFilter object from an SkReadBuffer.
+     *  Note: If the SkPictureImageFilter object construction requires bitmap
+     *  decoding, the decoder must be set on the SkReadBuffer parameter by calling
+     *  SkReadBuffer::setBitmapDecoder() before calling this constructor.
+     *  @param SkReadBuffer Serialized picture data.
+     */
+    explicit SkPictureImageFilter(SkReadBuffer&);
     virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
     virtual bool onFilterImage(Proxy*, const SkBitmap& src, const SkMatrix&,
                                SkBitmap* result, SkIPoint* offset) const SK_OVERRIDE;
 
 private:
     SkPicture* fPicture;
     SkRect     fRect;
     typedef SkImageFilter INHERITED;
 };
 
 #endif