small bug fix for batch asserts

src/gpu/GrInOrderDrawBuffer.cpp

Index: src/gpu/GrInOrderDrawBuffer.cpp
diff --git a/src/gpu/GrInOrderDrawBuffer.cpp b/src/gpu/GrInOrderDrawBuffer.cpp
index 8c2bea95a020f31f21832a70142738a07f53254a..fa38d9c9df979c78ebfde567f1781f89ccc77dc2 100644
--- a/src/gpu/GrInOrderDrawBuffer.cpp
+++ b/src/gpu/GrInOrderDrawBuffer.cpp
@@ -399,7 +399,7 @@ void GrInOrderDrawBuffer::onDrawBatch(GrBatch* batch,
     }
 
     // Check if there is a Batch Draw we can batch with
-    if (Cmd::kDrawBatch_Cmd != fCmdBuffer.back().type()) {
+    if (Cmd::kDrawBatch_Cmd != fCmdBuffer.back().type() || !fDrawBatch) {
         fDrawBatch = GrNEW_APPEND_TO_RECORDER(fCmdBuffer, DrawBatch, (batch, &fBatchTarget));
         this->recordTraceMarkersIfNecessary(fDrawBatch);
         return;