Iterate over instanced draws in GrGpu rather than above GrBatchTarget

src/gpu/GrAARectRenderer.cpp

Index: src/gpu/GrAARectRenderer.cpp
diff --git a/src/gpu/GrAARectRenderer.cpp b/src/gpu/GrAARectRenderer.cpp
index 7940e96b8431be93bcc8c2ad974e70f0efba146d..d208597fbb38e9690cf132db7623a343e920667f 100644
--- a/src/gpu/GrAARectRenderer.cpp
+++ b/src/gpu/GrAARectRenderer.cpp
@@ -140,7 +140,7 @@ public:
                                              canTweakAlphaForCoverage);
         }
 
-        helper.issueDraws(batchTarget);
+        helper.issueDraw(batchTarget);
     }
 
     SkSTArray<1, Geometry, true>* geoData() { return &fGeoData; }
@@ -505,7 +505,7 @@ public:
                                                args.fMiterStroke,
                                                canTweakAlphaForCoverage);
         }
-        helper.issueDraws(batchTarget);
+        helper.issueDraw(batchTarget);
     }
 
     SkSTArray<1, Geometry, true>* geoData() { return &fGeoData; }