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

services/ui/ws/window_tree_host_factory.h

Index: services/ui/ws/window_tree_host_factory.h
diff --git a/services/ui/ws/window_tree_host_factory.h b/services/ui/ws/window_tree_host_factory.h
index 0fa3d514e6935dc884864eaa9f070cb5d7a71e2c..f1461744b8b9d758fe098de80f26e1686a073387 100644
--- a/services/ui/ws/window_tree_host_factory.h
+++ b/services/ui/ws/window_tree_host_factory.h
@@ -9,7 +9,6 @@
 
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "services/ui/public/interfaces/window_tree_host.mojom.h"
-#include "services/ui/ws/platform_display_init_params.h"
 #include "services/ui/ws/user_id.h"
 
 namespace ui {
@@ -31,7 +30,6 @@ class WindowTreeHostFactory : public mojom::WindowTreeHostFactory {
 
   WindowServer* window_server_;
   const UserId user_id_;
-  PlatformDisplayInitParams platform_display_init_params_;
   mojo::BindingSet<mojom::WindowTreeHostFactory> bindings_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeHostFactory);