Add SkPngChunkReader.

src/images/SkImageDecoder.cpp

 /*
  * Copyright 2006 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.
  */
 
 
 #include "SkImageDecoder.h"
 #include "SkBitmap.h"
@@ skipping 65 matching lines @@
         case kWBMP_Format:
             return "WBMP";
         case kWEBP_Format:
             return "WEBP";
         default:
             SkDEBUGFAIL("Invalid format type!");
     }
     return "Unknown Format";
 }
 
-SkImageDecoder::Peeker* SkImageDecoder::setPeeker(Peeker* peeker) {
+SkChunkReader* SkImageDecoder::setPeeker(SkChunkReader* peeker) {
     SkRefCnt_SafeAssign(fPeeker, peeker);
     return peeker;
 }
 
 SkBitmap::Allocator* SkImageDecoder::setAllocator(SkBitmap::Allocator* alloc) {
     SkRefCnt_SafeAssign(fAllocator, alloc);
     return alloc;
 }
 
 void SkImageDecoder::setSampleSize(int size) {
@@ skipping 168 matching lines @@
     return success;
 }
 
 bool SkImageDecoder::decodeYUV8Planes(SkStream* stream, SkISize componentSizes[3], void* planes[3],
                                       size_t rowBytes[3], SkYUVColorSpace* colorSpace) {
     // we reset this to false before calling onDecodeYUV8Planes
     fShouldCancelDecode = false;
 
     return this->onDecodeYUV8Planes(stream, componentSizes, planes, rowBytes, colorSpace);
 }