Update some uses of char16 to use the base:: namespace.

ash/system/user/tray_user.cc

 // Copyright (c) 2012 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.
 
 #include "ash/system/user/tray_user.h"
 
 #include <algorithm>
 #include <climits>
 #include <vector>
 
@@ skipping 71 matching lines @@
 
 // When a hover border is used, it is starting this many pixels before the icon
 // position.
 const int kTrayUserTileHoverBorderInset = 10;
 
 // The border color of the user button.
 const SkColor kBorderColor = 0xffdcdcdc;
 
 // The invisible word joiner character, used as a marker to indicate the start
 // and end of the user's display name in the public account user card's text.
-const char16 kDisplayNameMark[] = { 0x2060, 0 };
+const base::char16 kDisplayNameMark[] = { 0x2060, 0 };
 
 const int kPublicAccountLogoutButtonBorderImagesNormal[] = {
     IDR_AURA_TRAY_POPUP_PUBLIC_ACCOUNT_LOGOUT_BUTTON_BORDER,
     IDR_AURA_TRAY_POPUP_LABEL_BUTTON_NORMAL_BACKGROUND,
     IDR_AURA_TRAY_POPUP_LABEL_BUTTON_NORMAL_BACKGROUND,
     IDR_AURA_TRAY_POPUP_PUBLIC_ACCOUNT_LOGOUT_BUTTON_BORDER,
     IDR_AURA_TRAY_POPUP_LABEL_BUTTON_NORMAL_BACKGROUND,
     IDR_AURA_TRAY_POPUP_LABEL_BUTTON_NORMAL_BACKGROUND,
     IDR_AURA_TRAY_POPUP_PUBLIC_ACCOUNT_LOGOUT_BUTTON_BORDER,
     IDR_AURA_TRAY_POPUP_LABEL_BUTTON_NORMAL_BACKGROUND,
@@ skipping 1315 matching lines @@
       internal::GetRootWindowController(
           system_tray()->GetWidget()->GetNativeWindow()->GetRootWindow());
   if (controller && controller->shelf()) {
     UpdateAfterShelfAlignmentChange(
         controller->GetShelfLayoutManager()->GetAlignment());
   }
 }
 
 }  // namespace internal
 }  // namespace ash