Make File-Picker modal on Linux

ui/views/widget/desktop_aura/x11_desktop_handler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/widget/desktop_aura/x11_desktop_handler.h"
 
 #include <X11/Xatom.h>
 #include <X11/Xlib.h>
 
 #include "base/message_loop/message_loop.h"
@@ skipping 210 matching lines @@
       old_host->HandleNativeWidgetActivationChanged(false);
   }
 
   // Update the current window ID to effectively change the active widget.
   current_window_ = xid;
   current_window_active_state_ = active_state;
 
   if (active_state == ACTIVE) {
     DesktopWindowTreeHostX11* new_host =
         views::DesktopWindowTreeHostX11::GetHostForXID(xid);
-    if (new_host)
-      new_host->HandleNativeWidgetActivationChanged(true);
+    if (new_host) {
+      // Set focus to the modal dialog instead of the host window.
+      if (new_host->GetModalDialog()) {
+        XSetInputFocus(xdisplay_, new_host->GetModalDialog(),
+            RevertToParent, CurrentTime);
+      } else {
+        new_host->HandleNativeWidgetActivationChanged(true);
+      }
+    }
   }
 }
 
 void X11DesktopHandler::OnWindowCreatedOrDestroyed(int event_type,
                                                    XID window) {
   // Menus created by Chrome can be drag and drop targets. Since they are
   // direct children of the screen root window and have override_redirect
   // we cannot use regular _NET_CLIENT_LIST_STACKING property to find them
   // and use a separate cache to keep track of them.
   // TODO(varkha): Implement caching of all top level X windows and their
   // coordinates and stacking order to eliminate repeated calls to the X server
   // during mouse movement, drag and shaping events.
   if (event_type == CreateNotify) {
     // The window might be destroyed if the message pump did not get a chance to
     // run but we can safely ignore the X error.
     gfx::X11ErrorTracker error_tracker;
     ui::XMenuList::GetInstance()->MaybeRegisterMenu(window);
   } else {
     ui::XMenuList::GetInstance()->MaybeUnregisterMenu(window);
   }
 
   if (event_type == DestroyNotify) {
     // Notify the XForeignWindowManager that |window| has been destroyed.
     ui::XForeignWindowManager::GetInstance()->OnWindowDestroyed(window);
   }
 }
 
 }  // namespace views