exo: Set widget parent to target root window

components/exo/shell_surface.cc

Index: components/exo/shell_surface.cc
diff --git a/components/exo/shell_surface.cc b/components/exo/shell_surface.cc
index 0f0c8a65bdda247291e03b7cdd5f4d8991ffff57..f83d7ad00c9c1c0762e79d2b2c18e8f31366de74 100644
--- a/components/exo/shell_surface.cc
+++ b/components/exo/shell_surface.cc
@@ -887,8 +887,9 @@ void ShellSurface::CreateShellSurfaceWidget(ui::WindowShowState show_state) {
   params.shadow_type = views::Widget::InitParams::SHADOW_TYPE_NONE;
   params.opacity = views::Widget::InitParams::TRANSLUCENT_WINDOW;
   params.show_state = show_state;
-  params.parent =
-      ash::Shell::GetContainer(ash::Shell::GetPrimaryRootWindow(), container_);
+  // Make shell surface a transient child if |parent_| has been set.
+  params.parent = parent_ ? parent_ :

[reveman, 2016/07/29 18:27:07]

Pretty sure this will break xdg shell modal dialogs. Parent will be set in this
case but the widget should not be a child of the parent widget as that would
result in the dialog being moved if the parent was moved. that's not the
expected behavior. Can this be something like "parent_ ?
parent_->GetRootWindow()" instead and the transient child code below is kept as
it is?

fyi, gtk3-demo is useful to test xdg shell implementation.

[oshima, 2016/07/29 20:35:58]

That's still not right. Let's discuss offline.

[Dominik Laskowski, 2016/07/29 20:37:09]

Unless |params.child| is true, Widget::Init makes the widget a transient child
of |params.parent|, and then uses |params.parent| as a context to find a parent
root window. This is equivalent to the old code, except the root window is the
same as that of the parent.

I've verified that modal dialogs in gtk3-demo behave as expected, modulo an
unrelated bug where windows underneath can be focused.

+      ash::Shell::GetContainer(ash::Shell::GetTargetRootWindow(), container_);
   params.bounds = initial_bounds_;
   bool activatable = activatable_;
   // ShellSurfaces in system modal container are only activatable if input
@@ -924,10 +925,6 @@ void ShellSurface::CreateShellSurfaceWidget(ui::WindowShowState show_state) {
   widget_->set_movement_disabled(!initial_bounds_.IsEmpty());
   window_state->set_ignore_keyboard_bounds_change(!initial_bounds_.IsEmpty());
 
-  // Make shell surface a transient child if |parent_| has been set.
-  if (parent_)
-    wm::AddTransientChild(parent_, window);
-
   // Allow Ash to manage the position of a top-level shell surfaces if show
   // state is one that allows auto positioning and |initial_bounds_| has
   // not been set.