Start to decouple display::Display from ws::PlatformDisplay.

services/ui/ws/display.h

Index: services/ui/ws/display.h
diff --git a/services/ui/ws/display.h b/services/ui/ws/display.h
index 478f16a37a93e48de6cf96cb6940865af3e22bd2..f4b244d4f7fbc2987bd788457376e95a80926c9e 100644
--- a/services/ui/ws/display.h
+++ b/services/ui/ws/display.h
@@ -29,13 +29,16 @@
 #include "services/ui/ws/window_manager_window_tree_factory_set_observer.h"
 #include "ui/display/display.h"
 
+namespace display {
+struct ViewportMetrics;
+}
+
 namespace ui {
 namespace ws {
 
 class DisplayBinding;
 class DisplayManager;
 class FocusController;
-struct PlatformDisplayInitParams;
 class WindowManagerDisplayRoot;
 class WindowServer;
 class WindowTree;
@@ -65,19 +68,25 @@ class Display : public PlatformDisplayDelegate,
 
   // Initializes the display root ServerWindow and PlatformDisplay. Adds this to
   // DisplayManager as a pending display, until accelerated widget is available.
-  void Init(const PlatformDisplayInitParams& init_params,
+  void Init(const display::ViewportMetrics& metrics,
             std::unique_ptr<DisplayBinding> binding);
 
+  // Returns an ID for this display. In internal mode this the display::Display
+  // ID. In external mode this hasn't been defined yet.
   int64_t GetId() const;
 
+  // Sets the display::Display corresponding to this ws::Display. This is only
+  // valid in internal window mode.
+  void SetDisplay(const display::Display& display);
+
+  // PlatformDisplayDelegate:
+  const display::Display& GetDisplay() override;
+
   DisplayManager* display_manager();
   const DisplayManager* display_manager() const;
 
   PlatformDisplay* platform_display() { return platform_display_.get(); }
 
-  // Returns a display::Display corresponding to this ws::Display.
-  display::Display ToDisplay() const;
-
   // Returns the size of the display in physical pixels.
   gfx::Size GetSize() const;
 
@@ -168,7 +177,6 @@ class Display : public PlatformDisplayDelegate,
   void CreateRootWindow(const gfx::Size& size);
 
   // PlatformDisplayDelegate:
-  display::Display GetDisplay() override;
   ServerWindow* GetRootWindow() override;
   void OnAcceleratedWidgetAvailable() override;
   bool IsInHighContrastMode() override;
@@ -198,6 +206,10 @@ class Display : public PlatformDisplayDelegate,
   std::unique_ptr<PlatformDisplay> platform_display_;
   std::unique_ptr<FocusController> focus_controller_;
 
+  // In internal window mode this contains information about the display. In
+  // external window mode this will be invalid.
+  display::Display display_;
+
   // The last cursor set. Used to track whether we need to change the cursor.
   mojom::Cursor last_cursor_;