Be more explicit checking for render targets with MSAA render buffers

Previously, wrapping a non-0 FBO would always cause us to think it
was MSAA, causing it to be un-copyable.

Fixes https://github.com/flutter/flutter/issues/10284

Bug: skia:7412
Change-Id: If9c0f306ad8c0c3e23dee793a541a6852737f7d9
Reviewed-on: https://skia-review.googlesource.com/97100
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1 file changed