Prefix string16 with base:: in ui/.

ui/message_center/cocoa/settings_controller.mm

 // Copyright (c) 2013 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.
 
 #import "ui/message_center/cocoa/settings_controller.h"
 
 #include <algorithm>
 
 #include "base/mac/foundation_util.h"
 #import "base/mac/scoped_nsobject.h"
@@ skipping 174 matching lines @@
                                      kHorizontalMargin,
                                      NSWidth(fullFrame),
                                      NSHeight(fullFrame));
     groupDropDownButton_.reset(
         [[NSPopUpButton alloc] initWithFrame:dropDownButtonFrame
                                    pullsDown:YES]);
     [groupDropDownButton_ setAction:@selector(notifierGroupSelectionChanged:)];
     [groupDropDownButton_ setTarget:self];
     // Add a dummy item for pull-down.
     [groupDropDownButton_ addItemWithTitle:@""];
-    string16 title;
+    base::string16 title;
     for (size_t i = 0; i < groupCount; ++i) {
       const message_center::NotifierGroup& group =
           provider_->GetNotifierGroupAt(i);
-      string16 item = group.login_info.empty() ? group.name : group.login_info;
+      base::string16 item =
+          group.login_info.empty() ? group.name : group.login_info;
       [groupDropDownButton_ addItemWithTitle:base::SysUTF16ToNSString(item)];
       if (provider_->IsNotifierGroupActiveAt(i)) {
         title = item;
         [[groupDropDownButton_ lastItem] setState:NSOnState];
       }
     }
     [groupDropDownButton_ setTitle:base::SysUTF16ToNSString(title)];
     [groupDropDownButton_ sizeToFit];
     dropDownButtonFrame = [groupDropDownButton_ frame];
     dropDownButtonFrame.origin.y =
@@ skipping 120 matching lines @@
   NSPopUpButton* button = static_cast<NSPopUpButton*>(sender);
   // The first item is a dummy item.
   provider_->SwitchToNotifierGroup([button indexOfSelectedItem] - 1);
 }
 
 - (BOOL)notifierHasAdvancedSettings:(const message_center::NotifierId&)id {
   return provider_->NotifierHasAdvancedSettings(id);
 }
 
 @end