added native_window_set_buffer_count()

this method can be used to change the number of buffers
associated to a native window. the default is two.

Change-Id: I608b959e6b29d77f95edb23c31dc9b099a758f2f
diff --git a/include/surfaceflinger/Surface.h b/include/surfaceflinger/Surface.h
index 973780f..e4d60af 100644
--- a/include/surfaceflinger/Surface.h
+++ b/include/surfaceflinger/Surface.h
@@ -212,6 +212,7 @@
     int  dispatch_connect(va_list args);
     int  dispatch_disconnect(va_list args);
     int  dispatch_crop(va_list args);
+    int  dispatch_set_buffer_count(va_list args);
     
     void setUsage(uint32_t reqUsage);
     int  connect(int api);