Add SkPngChunkReader.

include/codec/SkCodec.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 SkCodec_DEFINED
 #define SkCodec_DEFINED
 
 #include "SkEncodedFormat.h"
 #include "SkImageGenerator.h"
 #include "SkImageInfo.h"
+#include "SkRefCnt.h"

[scroggo, 2015/03/27 19:19:58]

No longer needed.

[scroggo, 2015/04/01 14:53:48]

Done.

 #include "SkScanlineDecoder.h"
 #include "SkSize.h"
 #include "SkStream.h"
 #include "SkTemplates.h"
 #include "SkTypes.h"
 
 class SkData;
+class SkChunkReader;
 
 /**
  *  Abstraction layer directly on top of an image codec.
  */
 class SkCodec : public SkImageGenerator {
 public:
     /**
      *  If this stream represents an encoded image that we know how to decode,
      *  return an SkCodec that can decode it. Otherwise return NULL.
      *
      *  If NULL is returned, the stream is deleted immediately. Otherwise, the
      *  SkCodec takes ownership of it, and will delete it when done with it.
      */
-    static SkCodec* NewFromStream(SkStream*);
+    static SkCodec* NewFromStream(SkStream*, SkChunkReader* = NULL);
 
     /**
      *  If this data represents an encoded image that we know how to decode,
      *  return an SkCodec that can decode it. Otherwise return NULL.
      *
      *  Will take a ref if it returns a codec, else will not affect the data.
      */
-    static SkCodec* NewFromData(SkData*);
+    static SkCodec* NewFromData(SkData*, SkChunkReader* = NULL);
 
     /**
      *  Return a size that approximately supports the desired scale factor.
      *  The codec may not be able to scale efficiently to the exact scale
      *  factor requested, so return a size that approximates that scale.
      *
      *  FIXME: Move to SkImageGenerator?
      */
     SkISize getScaledDimensions(float desiredScale) const {
         return this->onGetScaledDimensions(desiredScale);
@@ skipping 110 matching lines @@
 #ifdef SK_SUPPORT_LEGACY_BOOL_ONGETINFO
     const SkImageInfo                   fInfo;
 #endif  //  SK_SUPPORT_LEGACY_BOOL_ONGETINFO
     SkAutoTDelete<SkStream>             fStream;
     bool                                fNeedsRewind;
     SkAutoTDelete<SkScanlineDecoder>    fScanlineDecoder;
 
     typedef SkImageGenerator INHERITED;
 };
 #endif // SkCodec_DEFINED