Incrementally flush GrDrawTarget

src/gpu/GrDrawTarget.h

Index: src/gpu/GrDrawTarget.h
diff --git a/src/gpu/GrDrawTarget.h b/src/gpu/GrDrawTarget.h
index b12ac99de4504c5766ef0f38c26d6a5d1f32224d..6aebba4ff3d05ca3c704833daa94c9199d047052 100644
--- a/src/gpu/GrDrawTarget.h
+++ b/src/gpu/GrDrawTarget.h
@@ -230,6 +230,9 @@ private:
     // Used only by CMM.
     void clearStencilClip(const SkIRect&, bool insideClip, GrRenderTarget*);
 
+    // flushes N batches, starting from index
+    inline void flushN(int index, int n);
+
     SkSTArray<256, SkAutoTUnref<GrBatch>, true> fBatches;
     SkAutoTDelete<GrClipMaskManager>            fClipMaskManager;
     // The context is only in service of the clip mask manager, remove once CMM doesn't need this.
@@ -238,6 +241,7 @@ private:
     GrResourceProvider*                         fResourceProvider;
     bool                                        fFlushing;
     GrBatchToken                                fLastFlushToken;
+    int                                         fLastFlushedBatch;
 
     typedef SkRefCnt INHERITED;
 };