Implement instanced rendering for simple shapes

src/gpu/batches/GrBatch.h

Index: src/gpu/batches/GrBatch.h
diff --git a/src/gpu/batches/GrBatch.h b/src/gpu/batches/GrBatch.h
index f0559330feb82db2764b1e444858d0d08ba3b13c..4e38b61775094a1162b077c1e6479914c79f5e92 100644
--- a/src/gpu/batches/GrBatch.h
+++ b/src/gpu/batches/GrBatch.h
@@ -141,6 +141,9 @@ private:
     virtual void onPrepare(GrBatchFlushState*) = 0;
     virtual void onDraw(GrBatchFlushState*) = 0;
 
+    // Override this method if the batch subclass gets allocated in a nonstandard way.
+    virtual void onDelete() const { delete this; }
+
     static uint32_t GenID(int32_t* idCounter) {
         // The atomic inc returns the old value not the incremented value. So we add
         // 1 to the returned value.
@@ -162,6 +165,12 @@ private:
     mutable uint32_t                    fUniqueID;
     static int32_t                      gCurrBatchUniqueID;
     static int32_t                      gCurrBatchClassID;
+
+    friend void GrTDeleteNonAtomicRef(const GrBatch*); // For onDelete.
 };
 
+inline void GrTDeleteNonAtomicRef(const GrBatch* batch) {
+    batch->onDelete();
+}
+
 #endif