Add SkPngChunkReader.

include/codec/SkCodec.h

Index: include/codec/SkCodec.h
diff --git a/include/codec/SkCodec.h b/include/codec/SkCodec.h
index 5a69d1367d69444423c736cbbfbfc0e259c6180f..dd40e68ae668e2a7c9d5f35527ab611280416759 100644
--- a/include/codec/SkCodec.h
+++ b/include/codec/SkCodec.h
@@ -11,6 +11,7 @@
 #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"
@@ -18,6 +19,7 @@
 #include "SkTypes.h"
 
 class SkData;
+class SkChunkReader;
 
 /**
  *  Abstraction layer directly on top of an image codec.
@@ -31,7 +33,7 @@ public:
      *  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,
@@ -39,7 +41,7 @@ public:
      *
      *  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.