Respect xfer barriers in InstancedRendering::Op

Fixes a bug introduced when this Op stopped storing a GrPipeline.

Change-Id: I1a39814cebe18b321ea369f005bb7759f233cfe6
Reviewed-on: https://skia-review.googlesource.com/10804
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
diff --git a/src/gpu/GrProcessorSet.cpp b/src/gpu/GrProcessorSet.cpp
index 21b20c7..8bdf6b6 100644
--- a/src/gpu/GrProcessorSet.cpp
+++ b/src/gpu/GrProcessorSet.cpp
@@ -149,6 +149,8 @@
     fIgnoresInputColor = SkToBool(props & GrXPFactory::AnalysisProperties::kIgnoresInputColor);
     fCompatibleWithCoverageAsAlpha &=
             SkToBool(props & GrXPFactory::AnalysisProperties::kCompatibleWithAlphaAsCoverage);
+    fRequiresBarrierBetweenOverlappingDraws = SkToBool(
+            props & GrXPFactory::AnalysisProperties::kRequiresBarrierBetweenOverlappingDraws);
     if (props & GrXPFactory::AnalysisProperties::kIgnoresInputColor) {
         fInitialColorProcessorsToEliminate = processors.numColorFragmentProcessors();
         // If the output of the last color stage is known then the kIgnoresInputColor optimization