Incrementally flush GrDrawTarget

src/gpu/GrBatchFlushState.h

Index: src/gpu/GrBatchFlushState.h
diff --git a/src/gpu/GrBatchFlushState.h b/src/gpu/GrBatchFlushState.h
index 5e68e282858e8fe4d49225b5f858955362212232..f9b304d6a25ad646477e45af5be49d9353bd68b6 100644
--- a/src/gpu/GrBatchFlushState.h
+++ b/src/gpu/GrBatchFlushState.h
@@ -46,7 +46,7 @@ class GrBatchFlushState {
 public:
     GrBatchFlushState(GrGpu*, GrResourceProvider*, GrBatchToken lastFlushedToken);
 
-    ~GrBatchFlushState() { SkASSERT(fLastFlushedToken == fCurrentToken); }
+    ~GrBatchFlushState() { this->reset(); }
 
     void advanceToken() { ++fCurrentToken; }
 
@@ -99,6 +99,11 @@ public:
 
     GrGpu* gpu() { return fGpu; }
 
+    void reset() {
+        fVertexPool.reset();
+        fIndexPool.reset();
+    }
+
 private:
     GrGpu*                                          fGpu;
     GrBatchUploader::TextureUploader                fUploader;