Makes display roots be destroyed by client

services/ui/ws/window_manager_state.h

Index: services/ui/ws/window_manager_state.h
diff --git a/services/ui/ws/window_manager_state.h b/services/ui/ws/window_manager_state.h
index 95a608cdceb0b4496a04a82087e804309326a298..718cae8224843ba33426a585446c089564148a90 100644
--- a/services/ui/ws/window_manager_state.h
+++ b/services/ui/ws/window_manager_state.h
@@ -16,6 +16,7 @@
 #include "services/ui/public/interfaces/display.mojom.h"
 #include "services/ui/ws/event_dispatcher.h"
 #include "services/ui/ws/event_dispatcher_delegate.h"
+#include "services/ui/ws/server_window_observer.h"
 #include "services/ui/ws/user_id.h"
 #include "services/ui/ws/window_server.h"
 
@@ -23,6 +24,7 @@ namespace ui {
 namespace ws {
 
 class DisplayManager;
+class WindowManagerDisplayRoot;
 class WindowTree;
 
 namespace test {
@@ -32,7 +34,8 @@ class WindowManagerStateTestApi;
 // Manages state specific to a WindowManager that is shared across displays.
 // WindowManagerState is owned by the WindowTree the window manager is
 // associated with.
-class WindowManagerState : public EventDispatcherDelegate {
+class WindowManagerState : public EventDispatcherDelegate,
+                           public ServerWindowObserver {
  public:
   explicit WindowManagerState(WindowTree* window_tree);
   ~WindowManagerState() override;
@@ -72,6 +75,11 @@ class WindowManagerState : public EventDispatcherDelegate {
 
   void AddSystemModalWindow(ServerWindow* window);
 
+  // Returns the ServerWindow corresponding to an orphaned root with the
+  // specified id. See |orphaned_window_manager_display_roots_| for details on
+  // what on orphaned root is.
+  ServerWindow* GetOrphanedRootWithId(const WindowId& id);
+
   // TODO(sky): EventDispatcher is really an implementation detail and should
   // not be exposed.
   EventDispatcher* event_dispatcher() { return &event_dispatcher_; }
@@ -98,6 +106,11 @@ class WindowManagerState : public EventDispatcherDelegate {
   friend class Display;
   friend class test::WindowManagerStateTestApi;
 
+  // Set of display roots. This is a vector rather than a set to support removal
+  // without deleting.
+  using WindowManagerDisplayRoots =
+      std::vector<std::unique_ptr<WindowManagerDisplayRoot>>;
+
   enum class DebugAcceleratorType {
     PRINT_WINDOWS,
   };
@@ -143,6 +156,14 @@ class WindowManagerState : public EventDispatcherDelegate {
   DisplayManager* display_manager();
   const DisplayManager* display_manager() const;
 
+  // Adds |display_root| to the set of WindowManagerDisplayRoots owned by this
+  // WindowManagerState.
+  void AddWindowManagerDisplayRoot(
+      std::unique_ptr<WindowManagerDisplayRoot> display_root);
+
+  // Called when a Display is deleted.
+  void OnDisplayDestroying(Display* display);
+
   // Sets the visibility of all window manager roots windows to |value|.
   void SetAllRootWindowsVisible(bool value);
 
@@ -206,6 +227,9 @@ class WindowManagerState : public EventDispatcherDelegate {
   ServerWindow* GetRootWindowContaining(gfx::Point* location) override;
   void OnEventTargetNotFound(const ui::Event& event) override;
 
+  // ServerWindowObserver:
+  void OnWindowEmbeddedAppDisconnected(ServerWindow* window) override;
+
   // The single WindowTree this WindowManagerState is associated with.
   // |window_tree_| owns this.
   WindowTree* window_tree_;
@@ -230,6 +254,16 @@ class WindowManagerState : public EventDispatcherDelegate {
   // PlatformDisplay that currently has capture.
   PlatformDisplay* platform_display_with_capture_ = nullptr;
 
+  // All the active WindowManagerDisplayRoots.
+  WindowManagerDisplayRoots window_manager_display_roots_;
+
+  // Set of WindowManagerDisplayRoots corresponding to Displays that have been
+  // destroyed. WindowManagerDisplayRoots are not destroyed immediately when
+  // the Display is destroyed to allow the client to destroy the window when it
+  // wants to. Once the client destroys the window WindowManagerDisplayRoots is
+  // destroyed.
+  WindowManagerDisplayRoots orphaned_window_manager_display_roots_;
+
   base::WeakPtrFactory<WindowManagerState> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowManagerState);