cashew: reset local counter on plan transition

src/device_impl.h

Index: src/device_impl.h
diff --git a/src/device_impl.h b/src/device_impl.h
index 8da64fbe1894f253ce276d5f5296c35c2fb984f6..e34d2cbdd4c59196cbfba6e3f77f3b3cebe36c43 100644
--- a/src/device_impl.h
+++ b/src/device_impl.h
@@ -54,10 +54,11 @@ class DeviceImpl : public Device,
     virtual bool StartByteCounter();
     virtual void StopByteCounter();
     virtual bool ByteCounterRunning() const;
+    virtual void ResetByteCounter(uint64 rx_bytes, uint64 tx_bytes);
 
     // ByteCounterDelegate methods
 
-    // called when bye counter is updated
+    // called when byte counter is updated
     virtual void OnByteCounterUpdate(const ByteCounter *counter,
                                      uint64 rx_bytes, uint64 tx_bytes);