Add context markup to integer texture test

Trying to get better information about what's failing (and make this
easier in the future).

BUG=skia:6086

Change-Id: Iedb1269abb4527170b919bd90bce625a7f78f05a
Reviewed-on: https://skia-review.googlesource.com/6584
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
1 file changed