Revert of Mandoline UI Process: Update namespaces and file names

components/mus/surfaces/surfaces_state.cc

Index: components/mus/surfaces/surfaces_state.cc
diff --git a/components/mus/surfaces/surfaces_state.cc b/components/mus/surfaces/surfaces_state.cc
index e3dfeb8d85dcaff9d41126819e0dff3733c8750f..6ae5118edb8113d83e42494c99aed261176550ca 100644
--- a/components/mus/surfaces/surfaces_state.cc
+++ b/components/mus/surfaces/surfaces_state.cc
@@ -4,10 +4,10 @@
 
 #include "components/mus/surfaces/surfaces_state.h"
 
-namespace mus {
+namespace surfaces {
 
 SurfacesState::SurfacesState() : next_id_namespace_(1u) {}
 
 SurfacesState::~SurfacesState() {}
 
-}  // namespace mus
+}  // namespace surfaces