Index: render_widget_host_view_mac.mm
===================================================================
--- render_widget_host_view_mac.mm	(revision 197225)
+++ render_widget_host_view_mac.mm	(working copy)
@@ -1424,7 +1424,7 @@
     // Forget IOSurface since we are drawing a software frame now.
     if (compositing_iosurface_.get() &&
         compositing_iosurface_->HasIOSurface()) {
-      compositing_iosurface_->UnrefIOSurface();
+      compositing_iosurface_->ClearDrawable();
     }
   }
 }