Change SkImageDecoders to take an SkStreamRewindable.

include/core/SkImageDecoder.h

Index: include/core/SkImageDecoder.h
diff --git a/include/core/SkImageDecoder.h b/include/core/SkImageDecoder.h
index a8cbe6341332e4efcffe751589736c7b67d01758..bff749538f9176ea1eb644efbdda04cf2b53d00c 100644
--- a/include/core/SkImageDecoder.h
+++ b/include/core/SkImageDecoder.h
@@ -19,6 +19,7 @@
 #include "SkTypes.h"
 
 class SkStream;
+class SkStreamRewindable;
 
 /** \class SkImageDecoder
 
@@ -46,10 +47,10 @@ public:
     */
     virtual Format getFormat() const;
 
-    /** Return the format of the SkStream or kUnknown_Format if it cannot be determined. Rewinds the
-        stream before returning.
+    /** Return the format of the SkStreamRewindable or kUnknown_Format if it cannot be determined.
+        Rewinds the stream before returning.
     */
-    static Format GetStreamFormat(SkStream*);
+    static Format GetStreamFormat(SkStreamRewindable*);
 
     /** Return a readable string of the Format provided.
     */
@@ -290,7 +291,7 @@ public:
      *
      * Return true for success or false on failure.
      */
-    bool buildTileIndex(SkStream*, int *width, int *height);
+    bool buildTileIndex(SkStreamRewindable*, int *width, int *height);
 
     /**
      * Decode a rectangle subset in the image.
@@ -312,7 +313,7 @@ public:
     /** Given a stream, this will try to find an appropriate decoder object.
         If none is found, the method returns NULL.
     */
-    static SkImageDecoder* Factory(SkStream*);
+    static SkImageDecoder* Factory(SkStreamRewindable*);
 
     /** Decode the image stored in the specified file, and store the result
         in bitmap. Return true for success or false on failure.
@@ -374,7 +375,7 @@ public:
     static bool DecodeMemoryToTarget(const void* buffer, size_t size, SkImage::Info* info,
                                      const SkBitmapFactory::Target* target);
 
-    /** Decode the image stored in the specified SkStream, and store the result
+    /** Decode the image stored in the specified SkStreamRewindable, and store the result
         in bitmap. Return true for success or false on failure.
 
         @param prefConfig If the PrefConfigTable is not set, prefer this config.
@@ -383,10 +384,10 @@ public:
         @param format On success, if format is non-null, it is set to the format
                       of the decoded stream. On failure it is ignored.
      */
-    static bool DecodeStream(SkStream* stream, SkBitmap* bitmap,
+    static bool DecodeStream(SkStreamRewindable* stream, SkBitmap* bitmap,
                              SkBitmap::Config prefConfig, Mode,
                              Format* format = NULL);
-    static bool DecodeStream(SkStream* stream, SkBitmap* bitmap) {
+    static bool DecodeStream(SkStreamRewindable* stream, SkBitmap* bitmap) {
         return DecodeStream(stream, bitmap, SkBitmap::kNo_Config,
                             kDecodePixels_Mode, NULL);
     }
@@ -411,7 +412,7 @@ protected:
 
     // If the decoder wants to support tiled based decoding,
     // this method must be overridden. This guy is called by buildTileIndex(...)
-    virtual bool onBuildTileIndex(SkStream*, int *width, int *height) {
+    virtual bool onBuildTileIndex(SkStreamRewindable*, int *width, int *height) {
         return false;
     }
 
@@ -522,7 +523,7 @@ class SkImageDecoderFactory : public SkRefCnt {
 public:
     SK_DECLARE_INST_COUNT(SkImageDecoderFactory)
 
-    virtual SkImageDecoder* newDecoder(SkStream*) = 0;
+    virtual SkImageDecoder* newDecoder(SkStreamRewindable*) = 0;
 
 private:
     typedef SkRefCnt INHERITED;
@@ -531,7 +532,7 @@ private:
 class SkDefaultImageDecoderFactory : SkImageDecoderFactory {
 public:
     // calls SkImageDecoder::Factory(stream)
-    virtual SkImageDecoder* newDecoder(SkStream* stream) {
+    virtual SkImageDecoder* newDecoder(SkStreamRewindable* stream) {
         return SkImageDecoder::Factory(stream);
     }
 };
@@ -561,7 +562,7 @@ DECLARE_DECODER_CREATOR(WEBPImageDecoder);
 
 // Typedefs to make registering decoder and formatter callbacks easier.
 // These have to be defined outside SkImageDecoder. :(
-typedef SkTRegistry<SkImageDecoder*(*)(SkStream*)>        SkImageDecoder_DecodeReg;
-typedef SkTRegistry<SkImageDecoder::Format(*)(SkStream*)> SkImageDecoder_FormatReg;
+typedef SkTRegistry<SkImageDecoder*(*)(SkStreamRewindable*)>        SkImageDecoder_DecodeReg;
+typedef SkTRegistry<SkImageDecoder::Format(*)(SkStreamRewindable*)> SkImageDecoder_FormatReg;
 
 #endif