Replace string16 with base::string16.

chrome/browser/bookmarks/bookmark_pasteboard_helper_mac.mm

 // 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 "chrome/browser/bookmarks/bookmark_pasteboard_helper_mac.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/files/file_path.h"
 #include "base/strings/sys_string_conversions.h"
@@ skipping 82 matching lines @@
 
   NSArray* urlsArr = [bookmarkPairs objectAtIndex:0];
   NSArray* titlesArr = [bookmarkPairs objectAtIndex:1];
   if ([urlsArr count] < 1)
     return false;
   if ([urlsArr count] != [titlesArr count])
     return false;
 
   NSUInteger len = [titlesArr count];
   for (NSUInteger i = 0; i < len; ++i) {
-    string16 title = base::SysNSStringToUTF16([titlesArr objectAtIndex:i]);
+    base::string16 title = base::SysNSStringToUTF16([titlesArr objectAtIndex:i]);
     std::string url = base::SysNSStringToUTF8([urlsArr objectAtIndex:i]);
     if (!url.empty()) {
       BookmarkNodeData::Element element;
       element.is_url = true;
       element.url = GURL(url);
       element.title = title;
       elements.push_back(element);
     }
   }
   return true;
@@ skipping 163 matching lines @@
 bool PasteboardContainsBookmarks(ui::ClipboardType type) {
   NSPasteboard* pb = PasteboardFromType(type);
 
   NSArray* availableTypes =
       [NSArray arrayWithObjects:kBookmarkDictionaryListPboardType,
                                 kCrWebURLsWithTitlesPboardType,
                                 NSURLPboardType,
                                 nil];
   return [pb availableTypeFromArray:availableTypes] != nil;
 }