Add GrOp::wasRecorded and use in instanced rendering for tracking.

BUG=skia:

Change-Id: I4c5cdf47d42b7adae3649c7f96caabe68f45acbf
Reviewed-on: https://skia-review.googlesource.com/9308
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Chris Dalton <csmartdalton@google.com>
diff --git a/src/gpu/instanced/InstancedRendering.cpp b/src/gpu/instanced/InstancedRendering.cpp
index 1ffaaa4..ef2264b 100644
--- a/src/gpu/instanced/InstancedRendering.cpp
+++ b/src/gpu/instanced/InstancedRendering.cpp
@@ -369,7 +369,10 @@
     }
     fInfo.fUsesLocalCoords = optimizations.readsLocalCoords();
     fInfo.fCannotTweakAlphaForCoverage = !optimizations.canTweakAlphaForCoverage();
+}
 
+void InstancedRendering::Op::wasRecorded() {
+    SkASSERT(!fIsTracked);
     fInstancedRendering->fTrackedOps.addToTail(this);
     fIsTracked = true;
 }