WIP: Propagate SurfaceID up window tree hierarchy

services/ui/ws/window_server.h

Index: services/ui/ws/window_server.h
diff --git a/services/ui/ws/window_server.h b/services/ui/ws/window_server.h
index 9eedec1760bb47fa529ca937154465b5e5e62c95..13258fda40fde7eb5635022abe0e6a48c12fcbf5 100644
--- a/services/ui/ws/window_server.h
+++ b/services/ui/ws/window_server.h
@@ -19,7 +19,8 @@
 #include "services/ui/public/interfaces/window_manager_window_tree_factory.mojom.h"
 #include "services/ui/public/interfaces/window_tree.mojom.h"
 #include "services/ui/public/interfaces/window_tree_host.mojom.h"
-#include "services/ui/surfaces/surfaces_state.h"
+#include "services/ui/surfaces/display_compositor.h"
+#include "services/ui/surfaces/display_compositor_client.h"
 #include "services/ui/ws/display.h"
 #include "services/ui/ws/gpu_service_proxy_delegate.h"
 #include "services/ui/ws/ids.h"
@@ -48,6 +49,7 @@ class WindowTreeBinding;
 // WindowTrees) as well as providing the root of the hierarchy.
 class WindowServer : public ServerWindowDelegate,
                      public ServerWindowObserver,
+                     public surfaces::DisplayCompositorClient,
                      public GpuServiceProxyDelegate,
                      public UserDisplayManagerDelegate,
                      public UserIdTrackerObserver {
@@ -176,6 +178,10 @@ class WindowServer : public ServerWindowDelegate,
   void ProcessWindowBoundsChanged(const ServerWindow* window,
                                   const gfx::Rect& old_bounds,
                                   const gfx::Rect& new_bounds);
+  void ProcessWindowSurfaceCreated(ServerWindow* window,
+                                   const gfx::Size& size,
+                                   float device_scale_factor,
+                                   const cc::SurfaceId& surface_id);
   void ProcessClientAreaChanged(
       const ServerWindow* window,
       const gfx::Insets& new_client_area,
@@ -232,7 +238,7 @@ class WindowServer : public ServerWindowDelegate,
   WindowManagerState* GetWindowManagerStateForUser(const UserId& user_id);
 
   // ServerWindowDelegate:
-  ui::SurfacesState* GetSurfacesState() override;
+  ui::surfaces::DisplayCompositor* GetDisplayCompositor() override;
 
   // UserDisplayManagerDelegate:
   bool GetFrameDecorationsForUser(
@@ -257,6 +263,11 @@ class WindowServer : public ServerWindowDelegate,
     uint32_t client_change_id;
   };
 
+  // DisplayCompositorClient implementation:
+  void OnSurfaceCreated(const gfx::Size& size,
+                        float device_scale_factor,
+                        const cc::SurfaceId& surface_id) override;
+
   using InFlightWindowManagerChangeMap =
       std::map<uint32_t, InFlightWindowManagerChange>;
 
@@ -345,7 +356,7 @@ class WindowServer : public ServerWindowDelegate,
   WindowServerDelegate* delegate_;
 
   // State for rendering into a Surface.
-  scoped_refptr<ui::SurfacesState> surfaces_state_;
+  scoped_refptr<ui::surfaces::DisplayCompositor> display_compositor_;
 
   // ID to use for next WindowTree.
   ClientSpecificId next_client_id_;