Make SkStream *not* ref counted.

src/utils/mac/SkStream_mac.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCGUtils.h"
 #include "SkStream.h"
 
-// This is used by CGDataProviderCreateWithData
+// These are used by CGDataProviderCreateWithData
 
 static void unref_proc(void* info, const void* addr, size_t size) {
     SkASSERT(info);
     ((SkRefCnt*)info)->unref();
 }
 
+static void delete_stream_proc(void* info, const void* addr, size_t size) {
+    SkASSERT(info);
+    SkStream* stream = (SkStream*)info;
+    SkASSERT(stream->getMemoryBase() == addr);
+    SkASSERT(stream->getLength() == size);
+    SkDELETE(stream);
+}
+
 // These are used by CGDataProviderSequentialCallbacks
 
 static size_t get_bytes_proc(void* info, void* buffer, size_t bytes) {
     SkASSERT(info);
     return ((SkStream*)info)->read(buffer, bytes);
 }
 
 static off_t skip_forward_proc(void* info, off_t bytes) {
     return ((SkStream*)info)->skip((size_t) bytes);
 }
 
 static void rewind_proc(void* info) {
     SkASSERT(info);
     ((SkStream*)info)->rewind();
 }
 
+// Used when info is an SkStream.
 static void release_info_proc(void* info) {
     SkASSERT(info);
-    ((SkStream*)info)->unref();
+    SkDELETE((SkStream*)info);
 }
 
 CGDataProviderRef SkCreateDataProviderFromStream(SkStream* stream) {
-    stream->ref();  // unref will be called when the provider is deleted
-
+    // TODO: Replace with SkStream::getData() when that is added. Then we only
+    // have one version of CGDataProviderCreateWithData (i.e. same release proc)
     const void* addr = stream->getMemoryBase();
     if (addr) {
         // special-case when the stream is just a block of ram
         return CGDataProviderCreateWithData(stream, addr, stream->getLength(),
-                                            unref_proc);
+                                            delete_stream_proc);
     }
 
     CGDataProviderSequentialCallbacks rec;
     sk_bzero(&rec, sizeof(rec));
     rec.version = 0;
     rec.getBytes = get_bytes_proc;
     rec.skipForward = skip_forward_proc;
     rec.rewind = rewind_proc;
     rec.releaseInfo = release_info_proc;
     return CGDataProviderCreateSequential(stream, &rec);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 #include "SkData.h"
 
 CGDataProviderRef SkCreateDataProviderFromData(SkData* data) {
     data->ref();
     return CGDataProviderCreateWithData(data, data->data(), data->size(),
                                             unref_proc);
 }