add a ClassID function to GrBatch

src/gpu/batches/GrAAHairLinePathRenderer.cpp

Index: src/gpu/batches/GrAAHairLinePathRenderer.cpp
diff --git a/src/gpu/batches/GrAAHairLinePathRenderer.cpp b/src/gpu/batches/GrAAHairLinePathRenderer.cpp
index c6bdd055bb9eccb8bbdbc8cb98416745984e7fe1..d17ed09da9deb43872f2a50902065964d74ea0a7 100644
--- a/src/gpu/batches/GrAAHairLinePathRenderer.cpp
+++ b/src/gpu/batches/GrAAHairLinePathRenderer.cpp
@@ -672,6 +672,8 @@ bool check_bounds(const SkMatrix& viewMatrix, const SkRect& devBounds, void* ver
 
 class AAHairlineBatch : public GrVertexBatch {
 public:
+    DEFINE_BATCH_CLASS_ID
+
     struct Geometry {
         GrColor fColor;
         uint8_t fCoverage;
@@ -716,8 +718,7 @@ private:
     typedef SkTArray<int, true> IntArray;
     typedef SkTArray<float, true> FloatArray;
 
-    AAHairlineBatch(const Geometry& geometry) {
-        this->initClassID<AAHairlineBatch>();
+    AAHairlineBatch(const Geometry& geometry) : INHERITED(ClassID()) {
         fGeoData.push_back(geometry);
 
         // compute bounds
@@ -785,6 +786,8 @@ private:
 
     BatchTracker fBatch;
     SkSTArray<1, Geometry, true> fGeoData;
+
+    typedef GrVertexBatch INHERITED;
 };
 
 void AAHairlineBatch::onPrepareDraws(Target* target) {