fix build on linux

GnorTech · rogerwang · commit 40486d8a7746 · 2014-06-18T10:55:15.000+08:00
diff --git a/src/browser/file_select_helper.cc b/src/browser/file_select_helper.cc
@@ -398,8 +398,13 @@ void FileSelectHelper::RunFileChooserOnUIThread(
   FilePath default_file_name = params.default_file_name;
   FilePath working_path      = params.initial_path;
 
+#if defined(OS_WIN)
   gfx::NativeWindow owning_window =
       (gfx::NativeWindow)::GetAncestor((HWND)render_view_host_->GetView()->GetNativeView(), GA_ROOT);
+#else
+  gfx::NativeWindow owning_window =
+      platform_util::GetTopLevel(render_view_host_->GetView()->GetNativeView());
+#endif
 
   select_file_dialog_->SelectFile(
       dialog_type_,
