Force AAType to MSAA if the render target has MSAA and the API doesn't support disabling it.

Change-Id: I88c29b8117fa82c6f41166b9333537a06bb841cc
Reviewed-on: https://skia-review.googlesource.com/19818
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/GrClipStackClip.cpp b/src/gpu/GrClipStackClip.cpp
index 15f9767..af5a7ba 100644
--- a/src/gpu/GrClipStackClip.cpp
+++ b/src/gpu/GrClipStackClip.cpp
@@ -120,7 +120,8 @@
         canDrawArgs.fShape = &shape;
         canDrawArgs.fAAType = GrChooseAAType(GrBoolToAA(element->isAA()),
                                              renderTargetContext->fsaaType(),
-                                             GrAllowMixedSamples::kYes);
+                                             GrAllowMixedSamples::kYes,
+                                             *context->caps());
         canDrawArgs.fHasUserStencilSettings = hasUserStencilSettings;
 
         // the 'false' parameter disallows use of the SW path renderer