Pass root ServerWindow id to FrameGenerator.

services/ui/ws/display.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 SERVICES_UI_WS_DISPLAY_H_
 #define SERVICES_UI_WS_DISPLAY_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 40 matching lines @@
 //   Display.
 // . without a DisplayBinding. In this mode a WindowManager is automatically
 //   created per user.
 class Display : public PlatformDisplayDelegate,
                 public mojom::WindowTreeHost,
                 public FocusControllerObserver,
                 public FocusControllerDelegate,
                 public UserIdTrackerObserver,
                 public WindowManagerWindowTreeFactorySetObserver {
  public:
-  Display(WindowServer* window_server,
-          const PlatformDisplayInitParams& platform_display_init_params);
+  Display(WindowServer* window_server, PlatformDisplayInitParams init_params);
   ~Display() override;
 
   // Initializes state that depends on the existence of a Display.
   void Init(std::unique_ptr<DisplayBinding> binding);
 
   int64_t GetId() const;
 
   DisplayManager* display_manager();
   const DisplayManager* display_manager() const;
 
@@ skipping 83 matching lines @@
   // Inits the necessary state once the display is ready.
   void InitWindowManagerDisplayRootsIfNecessary();
 
   // Creates the set of WindowManagerDisplayRoots from the
   // WindowManagerWindowTreeFactorySet.
   void CreateWindowManagerDisplayRootsFromFactories();
 
   void CreateWindowManagerDisplayRootFromFactory(
       WindowManagerWindowTreeFactory* factory);
 
+  // Creates the root ServerWindow for this display. The root window will have
+  // |size| in DIP.
+  void CreateRootWindow(const gfx::Size& size);
+
   // PlatformDisplayDelegate:
-  void CreateRootWindow(const gfx::Size& size) override;
   ServerWindow* GetRootWindow() override;
   bool IsInHighContrastMode() override;
   void OnEvent(const ui::Event& event) override;
   void OnNativeCaptureLost() override;
 
   // FocusControllerDelegate:
   bool CanHaveActiveChildren(ServerWindow* window) const override;
 
   // FocusControllerObserver:
   void OnActivationChanged(ServerWindow* old_active_window,
@@ skipping 24 matching lines @@
 
   WindowManagerDisplayRootMap window_manager_display_root_map_;
 
   DISALLOW_COPY_AND_ASSIGN(Display);
 };
 
 }  // namespace ws
 }  // namespace ui
 
 #endif  // SERVICES_UI_WS_DISPLAY_H_