commit 58421544808562973ad66b2e3b8f9da1c5b8a36f
author scroggo <scroggo@google.com> Wed Apr 01 11:25:20 2015 -0700
committer Commit bot <commit-bot@chromium.org> Wed Apr 01 11:25:20 2015 -0700
tree 31d6673ccc7fb00c2f4ec363c2ae2351268778f3
parent fb8307c6b78bfbaa5e969a9df0c007c232d6251d

SkCodec::onGetScanlineDecoder must call rewind.

This mirrors the behavior in onGetPixels, and allows the implementation
to share code for handling calls to rewindIfNeeded.

This also fixes a bug where getScanlineDecoder was calling
rewindIfNeeded and treating the result as a bool.

In SkPngCodec, factor out the code to call rewindIfNeeded, and call it
in both onGetPixels and onGetScanlineDecoder.

Update the test to include testing the scanline decoder. Rename "gen"
to "codec" now that it must be an SkCodec.

BUG=skia:3257

Depends on https://codereview.chromium.org/1048423003/ (DIFFERENT ISSUE).

Review URL: https://codereview.chromium.org/1050893002