Make block size a template parameter of SkTLList

src/gpu/batches/GrVertexBatch.h

Index: src/gpu/batches/GrVertexBatch.h
diff --git a/src/gpu/batches/GrVertexBatch.h b/src/gpu/batches/GrVertexBatch.h
index 8922c30e2a56b9701c41751c4256989934ecd47c..ba899cc3fc32317bf905211a5f83b31506f18979 100644
--- a/src/gpu/batches/GrVertexBatch.h
+++ b/src/gpu/batches/GrVertexBatch.h
@@ -77,7 +77,8 @@ private:
 
     // Array of DrawArray. There may be inline uploads between each DrawArray and each DrawArray
     // may use a different primitive processor.
-    SkTLList<DrawArray> fDrawArrays;
+    typedef SkTLList<DrawArray, 4> DrawArrayList;
+    DrawArrayList fDrawArrays;
 
     typedef GrDrawBatch INHERITED;
 };