Prefix string16 with base:: in ui/.

ui/views/widget/desktop_aura/desktop_root_window_host_x11.h

 // 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.
 
 #ifndef UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_ROOT_WINDOW_HOST_X11_H_
 #define UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_ROOT_WINDOW_HOST_X11_H_
 
 #include <X11/extensions/shape.h>
 #include <X11/Xlib.h>
 
@@ skipping 89 matching lines @@
   virtual void Deactivate() OVERRIDE;
   virtual bool IsActive() const OVERRIDE;
   virtual void Maximize() OVERRIDE;
   virtual void Minimize() OVERRIDE;
   virtual void Restore() OVERRIDE;
   virtual bool IsMaximized() const OVERRIDE;
   virtual bool IsMinimized() const OVERRIDE;
   virtual bool HasCapture() const OVERRIDE;
   virtual void SetAlwaysOnTop(bool always_on_top) OVERRIDE;
   virtual bool IsAlwaysOnTop() const OVERRIDE;
-  virtual bool SetWindowTitle(const string16& title) OVERRIDE;
+  virtual bool SetWindowTitle(const base::string16& title) OVERRIDE;
   virtual void ClearNativeFocus() OVERRIDE;
   virtual Widget::MoveLoopResult RunMoveLoop(
       const gfx::Vector2d& drag_offset,
       Widget::MoveLoopSource source,
       Widget::MoveLoopEscapeBehavior escape_behavior) OVERRIDE;
   virtual void EndMoveLoop() OVERRIDE;
   virtual void SetVisibilityChangedAnimationsEnabled(bool value) OVERRIDE;
   virtual bool ShouldUseNativeFrame() OVERRIDE;
   virtual void FrameTypeChanged() OVERRIDE;
   virtual NonClientFrameView* CreateNonClientFrameView() OVERRIDE;
@@ skipping 156 matching lines @@
   // can notify widgets when they have lost capture, which controls a bunch of
   // things in views like hiding menus.
   static DesktopRootWindowHostX11* g_current_capture;
 
   // A list of all (top-level) windows that have been created but not yet
   // destroyed.
   static std::list<XID>* open_windows_;
 
   scoped_ptr<X11ScopedCapture> x11_capture_;
 
-  string16 window_title_;
+  base::string16 window_title_;
 
   DISALLOW_COPY_AND_ASSIGN(DesktopRootWindowHostX11);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_ROOT_WINDOW_HOST_X11_H_