Make SkStream *not* ref counted.

src/images/SkImageDecoder_libwebp.cpp

 /*
  * Copyright 2010, The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
@@ skipping 77 matching lines @@
         if (sk_64_asS32(size) > (0x7FFFFFFF >> 2)) {
             return false;
         }
     }
     return true;
 }
 
 class SkWEBPImageDecoder: public SkImageDecoder {
 public:
     SkWEBPImageDecoder() {
-        fInputStream = NULL;
         fOrigWidth = 0;
         fOrigHeight = 0;
         fHasAlpha = 0;
     }
-    virtual ~SkWEBPImageDecoder() {
-        SkSafeUnref(fInputStream);
-    }
 
     Format getFormat() const SK_OVERRIDE {
         return kWEBP_Format;
     }
 
 protected:
     bool onBuildTileIndex(SkStreamRewindable *stream, int *width, int *height) SK_OVERRIDE;
     bool onDecodeSubset(SkBitmap* bitmap, const SkIRect& rect) SK_OVERRIDE;
     Result onDecode(SkStream* stream, SkBitmap* bm, Mode) SK_OVERRIDE;
 
 private:
     /**
      *  Called when determining the output config to request to webp.
      *  If the image does not have alpha, there is no need to premultiply.
      *  If the caller wants unpremultiplied colors, that is respected.
      */
     bool shouldPremultiply() const {
         return SkToBool(fHasAlpha) && !this->getRequireUnpremultipliedColors();
     }
 
     bool setDecodeConfig(SkBitmap* decodedBitmap, int width, int height);
 
-    SkStream* fInputStream;
+    SkAutoTDelete<SkStream> fInputStream;
     int fOrigWidth;
     int fOrigHeight;
     int fHasAlpha;
 
     typedef SkImageDecoder INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////
 
 #ifdef TIME_DECODE
@@ skipping 170 matching lines @@
             alphaType = kUnpremul_SkAlphaType;
         } else {
             alphaType = kPremul_SkAlphaType;
         }
     }
     return decodedBitmap->setInfo(SkImageInfo::Make(width, height, colorType, alphaType));
 }
 
 bool SkWEBPImageDecoder::onBuildTileIndex(SkStreamRewindable* stream,
                                           int *width, int *height) {
+    SkAutoTDelete<SkStreamRewindable> streamDeleter(stream);
     int origWidth, origHeight, hasAlpha;
     if (!webp_parse_header(stream, &origWidth, &origHeight, &hasAlpha)) {
         return false;
     }
 
     if (!stream->rewind()) {
         SkDebugf("Failed to rewind webp stream!");
         return false;
     }
 
     *width = origWidth;
     *height = origHeight;
 
-    SkRefCnt_SafeAssign(this->fInputStream, stream);
+    this->fInputStream.reset(streamDeleter.detach());
     this->fOrigWidth = origWidth;
     this->fOrigHeight = origHeight;
     this->fHasAlpha = hasAlpha;
 
     return true;
 }
 
 static bool is_config_compatible(const SkBitmap& bitmap) {
     const SkColorType ct = bitmap.colorType();
     return ct == kARGB_4444_SkColorType || ct == kRGB_565_SkColorType || ct == kN32_SkColorType;
@@ skipping 330 matching lines @@
     return SkImageDecoder::kUnknown_Format;
 }
 
 static SkImageEncoder* sk_libwebp_efactory(SkImageEncoder::Type t) {
       return (SkImageEncoder::kWEBP_Type == t) ? SkNEW(SkWEBPImageEncoder) : NULL;
 }
 
 static SkImageDecoder_DecodeReg gDReg(sk_libwebp_dfactory);
 static SkImageDecoder_FormatReg gFormatReg(get_format_webp);
 static SkImageEncoder_EncodeReg gEReg(sk_libwebp_efactory);