tree dc2eef08cc61ea8b73d4650c0633b215b5aab37f
parent 93c69fff535075e86596a2b224f52f454b060be3
author scroggo <scroggo@google.com> 1448295280 -0800
committer Commit bot <commit-bot@chromium.org> 1448295280 -0800

Add SkPngChunkReader.

This class allows a client of SkCodec to read chunks in the data
stream that are not recognized by libpng. This is used by Android
to specify ninepatch data.

Taken from SkImageDecoder::Peeker. Modify the name of the class
and its method to be more specific to their use. Make
SkImageDecoder::Peeker a subclass of the new class, to help stage
the change in Android.

Add a test to verify that it works.

BUG=skia:4574
BUG=skia:3257

Committed: https://skia.googlesource.com/skia/+/3389e00136188800b98ca69488c0418c374fd78b

Review URL: https://codereview.chromium.org/1040453002