Replaces ::ui:: with ui:: in ash

ash/mus/screenlock_layout.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ASH_MUS_SCREENLOCK_LAYOUT_H_
 #define ASH_MUS_SCREENLOCK_LAYOUT_H_
 
 #include "ash/mus/layout_manager.h"
 #include "base/macros.h"
 
 namespace ash {
 namespace mus {
 
 // Lays out the shelf within shelf containers.
 class ScreenlockLayout : public LayoutManager {
  public:
-  explicit ScreenlockLayout(::ui::Window* owner);
+  explicit ScreenlockLayout(ui::Window* owner);
   ~ScreenlockLayout() override;
 
  private:
   // Overridden from LayoutManager:
-  void LayoutWindow(::ui::Window* window) override;
+  void LayoutWindow(ui::Window* window) override;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenlockLayout);
 };
 
 }  // namespace mus
 }  // namespace ash
 
 #endif  // ASH_MUS_SCREENLOCK_LAYOUT_H_