Mus: Introduce DisplayCompositorClient mojo interface

services/ui/surfaces/display_compositor.h

Index: services/ui/surfaces/display_compositor.h
diff --git a/services/ui/surfaces/display_compositor.h b/services/ui/surfaces/display_compositor.h
index 2498bac10c0091d389213ee3d34eeb4da6e8319b..13846d497b6b9833039e71b4dad3e387be22d4de 100644
--- a/services/ui/surfaces/display_compositor.h
+++ b/services/ui/surfaces/display_compositor.h
@@ -9,6 +9,7 @@
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "cc/ipc/display_compositor.mojom.h"
 #include "cc/surfaces/surface_manager.h"
 #include "cc/surfaces/surface_observer.h"
 
@@ -29,7 +30,7 @@ class DisplayCompositorClient;
 class DisplayCompositor : public cc::SurfaceObserver,
                           public base::RefCounted<DisplayCompositor> {
  public:
-  explicit DisplayCompositor(DisplayCompositorClient* client);
+  explicit DisplayCompositor(cc::mojom::DisplayCompositorClientPtr client);
 
   uint32_t GenerateNextClientId();
 
@@ -48,7 +49,7 @@ class DisplayCompositor : public cc::SurfaceObserver,
   void OnSurfaceDamaged(const cc::SurfaceId& surface_id,
                         bool* changed) override;
 
-  DisplayCompositorClient* const client_;
+  cc::mojom::DisplayCompositorClientPtr client_;
   uint32_t next_client_id_;
   cc::SurfaceManager manager_;