ui: Cleanup class/struct forward declarations

cc/surfaces/surface.cc

Index: cc/surfaces/surface.cc
diff --git a/cc/surfaces/surface.cc b/cc/surfaces/surface.cc
index 1c268d968ba70161d6e834771a4f0bc05b335964..cc3de978b3068df4fee0773f585eec72d766a1ea 100644
--- a/cc/surfaces/surface.cc
+++ b/cc/surfaces/surface.cc
@@ -22,10 +22,10 @@ namespace cc {
 // completely damaged the first time they're drawn from.
 static const int kFrameIndexStart = 2;
 
-Surface::Surface(const SurfaceId& id, SurfaceFactory* factory)
+Surface::Surface(const SurfaceId& id, base::WeakPtr<SurfaceFactory> factory)
     : surface_id_(id),
       previous_frame_surface_id_(id),
-      factory_(factory->AsWeakPtr()),
+      factory_(factory),
       frame_index_(kFrameIndexStart),
       destroyed_(false) {}