Reland of add a ClassID function to GrBatch

src/gpu/batches/GrDrawVerticesBatch.h

Index: src/gpu/batches/GrDrawVerticesBatch.h
diff --git a/src/gpu/batches/GrDrawVerticesBatch.h b/src/gpu/batches/GrDrawVerticesBatch.h
index aaa7b09812dee6b3b8f093af0f58171ec5b52d8c..49e93c8370e15543dd0e7093a57282d1ed841483 100644
--- a/src/gpu/batches/GrDrawVerticesBatch.h
+++ b/src/gpu/batches/GrDrawVerticesBatch.h
@@ -20,6 +20,8 @@
 
 class GrDrawVerticesBatch : public GrVertexBatch {
 public:
+    DEFINE_BATCH_CLASS_ID
+
     struct Geometry {
         GrColor fColor;
         SkTDArray<SkPoint> fPositions;
@@ -91,6 +93,8 @@
 
     BatchTracker fBatch;
     SkSTArray<1, Geometry, true> fGeoData;
+
+    typedef GrVertexBatch INHERITED;
 };
 
 #endif