Fall back dmsaa to default path on d3d11 backend

Currently fMSAAResolvesAutomatically would be enabled when the
system supports 'GL_EXT_multisampled_render_to_texture'. While
for d3d11 backend, this path with automatically resolving still
has some bugs[1] need to be fixed. We could make this path fall
back to the default path before that still uses two different
fbos. By doing this, we  could guarantee this dmsaa path is usable
for d3d11 backend in the functionality. Besides, some graphics
workloads could be benefited by the dmsaa fast path.

[1] https://bugs.chromium.org/p/angleproject/issues/detail?id=6030

Change-Id: I949024e7c3546f05af4eea45ef7959e9f1078b52
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/545616
Commit-Queue: Greg Daniel <egdaniel@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
Reviewed-by: Ravi Mistry <rmistry@google.com>
1 file changed