[Cleanup] Remove StringPrintf from global namespace

ash/display/display_manager.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/display/display_manager.h"
 
 #include <set>
 #include <string>
 #include <vector>
 
@@ skipping 508 matching lines @@
   std::vector<DisplayInfo> new_display_info_list;
   new_display_info_list.push_back(
       GetDisplayInfo(DisplayController::GetPrimaryDisplay()));
   // Add if there is only one display.
   if (displays_.size() == 1) {
     // Layout the 2nd display below the primary as with the real device.
     aura::RootWindow* primary = Shell::GetPrimaryRootWindow();
     gfx::Rect host_bounds =
         gfx::Rect(primary->GetHostOrigin(),  primary->GetHostSize());
     new_display_info_list.push_back(DisplayInfo::CreateFromSpec(
-        StringPrintf("%d+%d-500x400", host_bounds.x(), host_bounds.bottom())));
+        base::StringPrintf(
+            "%d+%d-500x400", host_bounds.x(), host_bounds.bottom())));
   }
   UpdateDisplays(new_display_info_list);
 }
 
 void DisplayManager::ScaleDisplayImpl() {
   DCHECK(!displays_.empty());
   std::vector<DisplayInfo> new_display_info_list;
   for (DisplayList::const_iterator iter = displays_.begin();
        iter != displays_.end(); ++iter) {
     DisplayInfo display_info = GetDisplayInfo(*iter);
@@ skipping 105 matching lines @@
   // always (0,0) and the secondary display's bounds will be updated
   // by |DisplayController::UpdateDisplayBoundsForLayout|.
   new_display.SetScaleAndBounds(
       display_info.device_scale_factor(), gfx::Rect(bounds_in_pixel.size()));
   new_display.set_rotation(display_info.rotation());
   return new_display;
 }
 
 }  // namespace internal
 }  // namespace ash