mus: Allow the WM to specify the windows that can have active children.

components/mus/ws/window_tree_host_impl.h

 // Copyright 2015 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.
 
 #ifndef COMPONENTS_MUS_WS_WINDOW_TREE_HOST_IMPL_H_
 #define COMPONENTS_MUS_WS_WINDOW_TREE_HOST_IMPL_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "components/mus/common/types.h"
@@ skipping 76 matching lines @@
   void UpdateTextInputState(ServerWindow* window,
                             const ui::TextInputState& state);
   void SetImeVisibility(ServerWindow* window, bool visible);
 
   // WindowTreeHost:
   void SetSize(mojo::SizePtr size) override;
   void SetTitle(const mojo::String& title) override;
   void AddAccelerator(uint32_t id,
                       mojom::EventMatcherPtr event_matcher) override;
   void RemoveAccelerator(uint32_t id) override;
+  void SetActivationParent(uint32_t window_id, bool enable) override;
 
  private:
   void OnClientClosed();
 
   // DisplayManagerDelegate:
   ServerWindow* GetRootWindow() override;
   void OnEvent(mojom::EventPtr event) override;
   void OnDisplayClosed() override;
   void OnViewportMetricsChanged(
       const mojom::ViewportMetrics& old_metrics,
       const mojom::ViewportMetrics& new_metrics) override;
   void OnTopLevelSurfaceChanged(cc::SurfaceId surface_id) override;
   void OnCompositorFrameDrawn() override;
 
   // FocusControllerDelegate:
+  bool CanHaveActiveChildren(ServerWindow* window) const override;
+  void OnActivationChanged(ServerWindow* old_active_window,
+                           ServerWindow* new_active_window) override;
   void OnFocusChanged(ServerWindow* old_focused_window,
                       ServerWindow* new_focused_window) override;
 
   // EventDispatcherDelegate:
   void OnAccelerator(uint32_t accelerator_id, mojom::EventPtr event) override;
   void SetFocusedWindowFromEventDispatcher(ServerWindow* window) override;
   ServerWindow* GetFocusedWindowForEventDispatcher() override;
   void DispatchInputEventToWindow(ServerWindow* target,
                                   bool in_nonclient_area,
                                   mojom::EventPtr event) override;
 
   // ServerWindowObserver:
   void OnWindowDestroyed(ServerWindow* window) override;
 
   WindowTreeHostDelegate* delegate_;
   ConnectionManager* const connection_manager_;
   mojom::WindowTreeHostClientPtr client_;
   EventDispatcher event_dispatcher_;
   scoped_ptr<ServerWindow> root_;
   scoped_ptr<DisplayManager> display_manager_;
   scoped_ptr<FocusController> focus_controller_;
   mojom::WindowManagerPtr window_manager_;
 
+  std::set<WindowId> activation_parents_;
+
   // Set of windows with surfaces that need to be destroyed once the frame
   // draws.
   std::set<ServerWindow*> windows_needing_frame_destruction_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeHostImpl);
 };
 
 }  // namespace ws
 }  // namespace mus
 
 #endif  // COMPONENTS_MUS_WS_WINDOW_TREE_HOST_IMPL_H_