Add flush before drawing lines workaround for Adreno 3xx

Bug: skia:6309
Change-Id: I354c678ca4e833c523a89b3196804fbe1adcf9d1
Reviewed-on: https://skia-review.googlesource.com/19087
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
4 files changed