Revert of Mus+Ash: propagate Surface ID to parents

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..a59fe9ee158053525f96db1094d87327d8dcf893 100644
--- a/services/ui/surfaces/display_compositor.h
+++ b/services/ui/surfaces/display_compositor.h
@@ -10,7 +10,6 @@
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "cc/surfaces/surface_manager.h"
-#include "cc/surfaces/surface_observer.h"
 
 namespace cc {
 class SurfaceHittest;
@@ -19,36 +18,26 @@
 
 namespace ui {
 
-class DisplayCompositorClient;
-
 // The DisplayCompositor object is an object global to the Window Server app
 // that holds the SurfaceServer and allocates new Surfaces namespaces.
 // This object lives on the main thread of the Window Server.
 // TODO(rjkroege, fsamuel): This object will need to change to support multiple
 // displays.
-class DisplayCompositor : public cc::SurfaceObserver,
-                          public base::RefCounted<DisplayCompositor> {
+class DisplayCompositor : public base::RefCounted<DisplayCompositor> {
  public:
-  explicit DisplayCompositor(DisplayCompositorClient* client);
+  DisplayCompositor();
 
   uint32_t GenerateNextClientId();
-
-  void ReturnSurfaceReference(const cc::SurfaceSequence& sequence);
 
   cc::SurfaceManager* manager() { return &manager_; }
 
  private:
   friend class base::RefCounted<DisplayCompositor>;
-  virtual ~DisplayCompositor();
+  ~DisplayCompositor();
 
-  // cc::SurfaceObserver implementation.
-  void OnSurfaceCreated(const cc::SurfaceId& surface_id,
-                        const gfx::Size& frame_size,
-                        float device_scale_factor) override;
-  void OnSurfaceDamaged(const cc::SurfaceId& surface_id,
-                        bool* changed) override;
-
-  DisplayCompositorClient* const client_;
+  // A Surface ID is an unsigned 64-bit int where the high 32-bits are generated
+  // by the Surfaces service, and the low 32-bits are generated by the process
+  // that requested the Surface.
   uint32_t next_client_id_;
   cc::SurfaceManager manager_;