Fix a recent regression in Speech->Start Speaking on Mac

content/browser/renderer_host/render_widget_host_view_mac.h

Index: content/browser/renderer_host/render_widget_host_view_mac.h
diff --git a/content/browser/renderer_host/render_widget_host_view_mac.h b/content/browser/renderer_host/render_widget_host_view_mac.h
index 5437503df3e73bfc6b8183e992c292b36e279e51..3626dd7f5c3604c937550259148ff089e5b53ab7 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.h
+++ b/content/browser/renderer_host/render_widget_host_view_mac.h
@@ -530,9 +530,6 @@ class CONTENT_EXPORT RenderWidgetHostViewMac
   // RenderWidgetHostViewGuest.
   bool is_guest_view_hack_;
 
-  // selected text on the renderer.
-  std::string selected_text_;
-
   // The window used for popup widgets.
   base::scoped_nsobject<NSWindow> popup_window_;