views/mus: Set-up transient windows correctly.

components/mus/ws/default_access_policy.cc

Index: components/mus/ws/default_access_policy.cc
diff --git a/components/mus/ws/default_access_policy.cc b/components/mus/ws/default_access_policy.cc
index 0a9cb241599f5832039db490b27f42fcffa3a0b2..ed10779bd6824267e9f537c39ee61106acff385d 100644
--- a/components/mus/ws/default_access_policy.cc
+++ b/components/mus/ws/default_access_policy.cc
@@ -37,18 +37,16 @@ bool DefaultAccessPolicy::CanAddWindow(const ServerWindow* parent,
 bool DefaultAccessPolicy::CanAddTransientWindow(
     const ServerWindow* parent,
     const ServerWindow* child) const {
-  return WasCreatedByThisConnection(child) &&
-         (delegate_->IsRootForAccessPolicy(parent->id()) ||
-          WasCreatedByThisConnection(parent));
+  return WasCreatedByThisConnection(child) ||
+         delegate_->IsRootForAccessPolicy(parent->id()) ||

[sky, 2015/11/19 20:32:10]

Thsi policy, and remove, is too loose. In particular it would allow a client to
parent a window to a window they should not be able to access. What specific
case are you encountering?

[sadrul, 2015/11/19 20:43:58]

In the window_type_launcher demo, trying to open a transient window fails,
because it owns neither of the windows (both are created by the WM).

[sky, 2015/11/19 21:27:14]

That implies you're trying to use a window from one windowtree with a window
from another windowtree. I'm not sure the client lib deals with that very well
yet. I believe we will need this logic, but it hinges on associated pipes.
Without them we don't have a way to know if window should be visible to you. I
think you should hold off on this until we get associated pipes in place.

+         WasCreatedByThisConnection(parent);
 }
 
 bool DefaultAccessPolicy::CanRemoveTransientWindowFromParent(
     const ServerWindow* window) const {
-  if (!WasCreatedByThisConnection(window))
-    return false;  // Can only unparent windows we created.
-
   return delegate_->IsRootForAccessPolicy(window->transient_parent()->id()) ||
-         WasCreatedByThisConnection(window->transient_parent());
+         WasCreatedByThisConnection(window->transient_parent()) ||
+         WasCreatedByThisConnection(window);
 }
 
 bool DefaultAccessPolicy::CanReorderWindow(