Make GrBatch carry its own GrPipeline

src/gpu/GrTargetCommands.cpp

Index: src/gpu/GrTargetCommands.cpp
diff --git a/src/gpu/GrTargetCommands.cpp b/src/gpu/GrTargetCommands.cpp
index 3067940c3f8976a7085af6052c0fc308021148dc..08c4d5bf5e36bac61c9e6143ba0eb265c10326df 100644
--- a/src/gpu/GrTargetCommands.cpp
+++ b/src/gpu/GrTargetCommands.cpp
@@ -30,8 +30,8 @@ void GrTargetCommands::flush(GrBufferedDrawTarget* bufferedDrawTarget) {
         if (Cmd::kDrawBatch_CmdType == genIter->type()) {
             DrawBatch* db = reinterpret_cast<DrawBatch*>(genIter.get());
             fBatchTarget.resetNumberOfDraws();
-            db->fBatch->generateGeometry(&fBatchTarget);
-            db->fBatch->setNumberOfDraws(fBatchTarget.numberOfDraws());
+            db->batch()->generateGeometry(&fBatchTarget);
+            db->batch()->setNumberOfDraws(fBatchTarget.numberOfDraws());
         }
     }