Eliminate ash::internal namespace

ash/wm/gestures/shelf_gesture_handler.cc

Index: ash/wm/gestures/shelf_gesture_handler.cc
diff --git a/ash/wm/gestures/shelf_gesture_handler.cc b/ash/wm/gestures/shelf_gesture_handler.cc
index 5e89737d24d1b5bd2f288ea07df36f9eb83c871c..42b12c5d40e11529806bd7ca18791388f29624e7 100644
--- a/ash/wm/gestures/shelf_gesture_handler.cc
+++ b/ash/wm/gestures/shelf_gesture_handler.cc
@@ -21,7 +21,6 @@
 #include "ui/views/widget/widget.h"
 
 namespace ash {
-namespace internal {
 
 ShelfGestureHandler::ShelfGestureHandler()
     : drag_in_progress_(false) {
@@ -93,5 +92,4 @@ bool ShelfGestureHandler::ProcessGestureEvent(const ui::GestureEvent& event) {
   return false;
 }
 
-}  // namespace internal
 }  // namespace ash