Make File-Picker modal on Linux

chrome/browser/ui/libgtk2ui/select_file_dialog_impl_gtk2.cc

Index: chrome/browser/ui/libgtk2ui/select_file_dialog_impl_gtk2.cc
diff --git a/chrome/browser/ui/libgtk2ui/select_file_dialog_impl_gtk2.cc b/chrome/browser/ui/libgtk2ui/select_file_dialog_impl_gtk2.cc
index 4cea81df9fd4eb23814576c79c8d4b6a2d8c500a..d37f9be03c1e32e364f41512be8e72cbd2f3e610 100644
--- a/chrome/browser/ui/libgtk2ui/select_file_dialog_impl_gtk2.cc
+++ b/chrome/browser/ui/libgtk2ui/select_file_dialog_impl_gtk2.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/browser/ui/libgtk2ui/select_file_dialog_impl_gtk2.h"
 
+#include <gdk/gdkx.h>
 #include <gtk/gtk.h>
 #include <stddef.h>
 #include <sys/stat.h>
@@ -33,6 +34,7 @@
 #include "ui/events/platform/x11/x11_event_source.h"
 #include "ui/shell_dialogs/select_file_dialog.h"
 #include "ui/strings/grit/ui_strings.h"
+#include "ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h"
 
 namespace {
 
@@ -48,6 +50,12 @@ void OnFileFilterDataDestroyed(std::string* file_extension) {
   delete file_extension;
 }
 
+// Runs DesktopWindowTreeHostX11::EnableEventListening() when the file-picker
+// is closed.
+void OnFilePickerDestroy(base::Closure* callback) {
+  callback->Run();
+}
+
 }  // namespace
 
 namespace libgtk2ui {
@@ -161,8 +169,16 @@ void SelectFileDialogImplGTK::SelectFileImpl(
 
   params_map_[dialog] = params;
 
-  // TODO(erg): Figure out how to fake GTK window-to-parent modality without
-  // having the parent be a real GtkWindow.
+  // Disable input events handling in the host window to make this dialog modal.
+  views::DesktopWindowTreeHostX11* host =
+      views::DesktopWindowTreeHostX11::GetHostForXID(
+      owning_window->GetHost()->GetAcceleratedWidget());
+  std::unique_ptr<base::Closure> callback = host->DisableEventListening(
+      GDK_WINDOW_XID(gtk_widget_get_window(dialog)));
+  // OnFilePickerDestroy() is called when |dialog| destroyed, which allows to
+  // invoke the callback function to re-enable events on the owning window.
+  g_object_set_data_full(G_OBJECT(dialog), "callback", callback.release(),
+      reinterpret_cast<GDestroyNotify>(OnFilePickerDestroy));
   gtk_window_set_modal(GTK_WINDOW(dialog), TRUE);
 
   gtk_widget_show_all(dialog);