aura-mus: Implement Deactivate().

services/ui/ws/window_tree.cc

Index: services/ui/ws/window_tree.cc
diff --git a/services/ui/ws/window_tree.cc b/services/ui/ws/window_tree.cc
index 4abe468092909ef7d03cdc6413366c6de8f17981..1ecebba57f34b88df9169d74ad8795a86d700a6f 100644
--- a/services/ui/ws/window_tree.cc
+++ b/services/ui/ws/window_tree.cc
@@ -1585,6 +1585,21 @@ void WindowTree::SetPredefinedCursor(uint32_t change_id,
   client()->OnChangeCompleted(change_id, success);
 }
 
+void WindowTree::DeactivateWindow(Id requester_window_id) {

[sky, 2017/01/12 00:55:39]

window_id

[Elliot Glaysher, 2017/01/12 23:20:37]

Done.

+  ServerWindow* window =
+      GetWindowByClientId(ClientWindowId(requester_window_id));
+  if (!window) {
+    DVLOG(1) << "ActivateNextWindow received invalid id.";
+    return;
+  }
+
+  WindowManagerDisplayRoot* display_root =

[sky, 2017/01/12 00:55:39]

Make sure you null check display_root. null happens if the window isn't parented
to a display. See other functions that use WindowManagerDisplayRoot for the set
of null checks.

[Elliot Glaysher, 2017/01/12 23:20:37]

Done.

+      GetWindowManagerDisplayRoot(window);
+  WindowTree* wm_tree = display_root->window_manager_state()->window_tree();
+  wm_tree->window_manager_internal_->WmDeactivateWindow(
+      wm_tree->ClientWindowIdForWindow(window).id);
+}
+
 void WindowTree::GetWindowManagerClient(
     mojo::AssociatedInterfaceRequest<mojom::WindowManagerClient> internal) {
   if (!access_policy_->CanSetWindowManager() || !window_manager_internal_ ||