Make SkStream *not* ref counted.

src/images/SkImageDecoder_libpng.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 "SkImageEncoder.h"
 #include "SkColor.h"
@@ skipping 35 matching lines @@
 SK_CONF_DECLARE(bool, c_suppressPNGImageDecoderWarnings,
                 "images.png.suppressDecoderWarnings",
                 DEFAULT_FOR_SUPPRESS_PNG_IMAGE_DECODER_WARNINGS,
                 "Suppress most PNG warnings when calling image decode "
                 "functions.");
 
 
 
 class SkPNGImageIndex {
 public:
+    // Takes ownership of stream.
     SkPNGImageIndex(SkStreamRewindable* stream, png_structp png_ptr, png_infop info_ptr)
         : fStream(stream)
         , fPng_ptr(png_ptr)
         , fInfo_ptr(info_ptr)
         , fColorType(kUnknown_SkColorType) {
         SkASSERT(stream != NULL);
-        stream->ref();
     }
     ~SkPNGImageIndex() {
         if (fPng_ptr) {
             png_destroy_read_struct(&fPng_ptr, &fInfo_ptr, png_infopp_NULL);
         }
     }
 
-    SkAutoTUnref<SkStreamRewindable>    fStream;
+    SkAutoTDelete<SkStreamRewindable>   fStream;
     png_structp                         fPng_ptr;
     png_infop                           fInfo_ptr;
     SkColorType                         fColorType;
 };
 
 class SkPNGImageDecoder : public SkImageDecoder {
 public:
     SkPNGImageDecoder() {
         fImageIndex = NULL;
     }
@@ skipping 630 matching lines @@
     }
 
     *colorTablep = SkNEW_ARGS(SkColorTable, (colorStorage, colorCount));
     *reallyHasAlphap = reallyHasAlpha;
     return true;
 }
 
 #ifdef SK_BUILD_FOR_ANDROID
 
 bool SkPNGImageDecoder::onBuildTileIndex(SkStreamRewindable* sk_stream, int *width, int *height) {
+    SkAutoTDelete<SkStreamRewindable> streamDeleter(sk_stream);
     png_structp png_ptr;
     png_infop   info_ptr;
 
     if (!onDecodeInit(sk_stream, &png_ptr, &info_ptr)) {
         return false;
     }
 
     if (setjmp(png_jmpbuf(png_ptr)) != 0) {
         png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL);
         return false;
     }
 
     png_uint_32 origWidth, origHeight;
     int bitDepth, colorType;
     png_get_IHDR(png_ptr, info_ptr, &origWidth, &origHeight, &bitDepth,
                  &colorType, int_p_NULL, int_p_NULL, int_p_NULL);
 
     *width = origWidth;
     *height = origHeight;
 
     png_build_index(png_ptr);
 
     if (fImageIndex) {
         SkDELETE(fImageIndex);
     }
-    fImageIndex = SkNEW_ARGS(SkPNGImageIndex, (sk_stream, png_ptr, info_ptr));
+    fImageIndex = SkNEW_ARGS(SkPNGImageIndex, (streamDeleter.detach(), png_ptr, info_ptr));
 
     return true;
 }
 
 bool SkPNGImageDecoder::onDecodeSubset(SkBitmap* bm, const SkIRect& region) {
     if (NULL == fImageIndex) {
         return false;
     }
 
     png_structp png_ptr = fImageIndex->fPng_ptr;
@@ skipping 512 matching lines @@
     return SkImageDecoder::kUnknown_Format;
 }
 
 SkImageEncoder* sk_libpng_efactory(SkImageEncoder::Type t) {
     return (SkImageEncoder::kPNG_Type == t) ? SkNEW(SkPNGImageEncoder) : NULL;
 }
 
 static SkImageDecoder_DecodeReg gDReg(sk_libpng_dfactory);
 static SkImageDecoder_FormatReg gFormatReg(get_format_png);
 static SkImageEncoder_EncodeReg gEReg(sk_libpng_efactory);