Make SkStream *not* ref counted.

SkStream is a stateful object, so it does not make sense for it to have
multiple owners. Make SkStream inherit directly from SkNoncopyable.

Update methods which previously called SkStream::ref() (e.g.
SkImageDecoder::buildTileIndex() and SkFrontBufferedStream::Create(),
which required the existing owners to call SkStream::unref()) to take
ownership of their SkStream parameters and delete when done (including
on failure).

Switch all SkAutoTUnref<SkStream>s to SkAutoTDelete<SkStream>s. In some
cases this means heap allocating streams that were previously stack
allocated.

Respect ownership rules of SkTypeface::CreateFromStream() and
SkImageDecoder::buildTileIndex().

Update the comments for exceptional methods which do not affect the
ownership of their SkStream parameters (e.g.
SkPicture::CreateFromStream() and SkTypeface::Deserialize()) to be
explicit about ownership.

Remove test_stream_life, which tested that buildTileIndex() behaved
correctly when SkStream was a ref counted object. The test does not
make sense now that it is not.

In SkPDFStream, remove the SkMemoryStream member. Instead of using it,
create a new SkMemoryStream to pass to fDataStream (which is now an
SkAutoTDelete).

Make other pdf rasterizers behave like SkPDFDocumentToBitmap.

SkPDFDocumentToBitmap delete the SkStream, so do the same in the
following pdf rasterizers:

SkPopplerRasterizePDF
SkNativeRasterizePDF
SkNoRasterizePDF

Requires a change to Android, which currently treats SkStreams as ref
counted objects.

Review URL: https://codereview.chromium.org/849103004

1 files changed, 4 insertions, 2 deletions

diff --git a/include/utils/SkFrontBufferedStream.h b/include/utils/SkFrontBufferedStream.h
index 68d9861557..bfc2728ef0 100644
--- a/include/utils/SkFrontBufferedStream.h
+++ b/include/utils/SkFrontBufferedStream.h
@@ -26,10 +26,12 @@ public:
      *  @param stream SkStream to buffer. If stream is NULL, NULL is
      *      returned. When this call succeeds (i.e. returns non NULL),
      *      SkFrontBufferedStream is expected to be the only owner of
-     *      stream, so it should be unreffed and no longer used directly.
+     *      stream, so it should no be longer used directly.
+     *      SkFrontBufferedStream will delete stream upon deletion.
      *  @param minBufferSize Minimum size of buffer required.
      *  @return An SkStream that can buffer at least minBufferSize, or
-     *      NULL on failure.
+     *      NULL on failure. The caller is required to delete when finished with
+     *      this object.
      */
     static SkStreamRewindable* Create(SkStream* stream, size_t minBufferSize);
 };