Fixing stripe test

Fixing stripe test

I originally thought that there was no harm in reading or skipping
zero lines after we have already reached the end of the image.

However, once we reach the end of the image, onFinish() is
automatically called.  Performing a read or a skip after
the call to onFinish() is invalid and will cause onFinish()
to be called a second time (which is also invalid).

Seems like the code requires good behavior and the test is
wrong.

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/f6db27e58e65a4c9680fdf00e41047578b6ac9f9

[msarett, 2015-06-12 15:47:31]

msarett@google.com changed reviewers:
+ emmaleer@google.com, scroggo@google.com

[msarett, 2015-06-12 16:04:52]

Patchset #1 (id:1) has been deleted

[scroggo, 2015-06-12 16:19:47]

lgtm

[msarett, 2015-06-12 16:28:18]

The CQ bit was checked by msarett@google.com

[commit-bot: I haz the power, 2015-06-12 16:28:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1179213002/20001

[commit-bot: I haz the power, 2015-06-12 16:34:08]

Committed patchset #1 (id:20001) as
https://skia.googlesource.com/skia/+/f6db27e58e65a4c9680fdf00e41047578b6ac9f9