ui/base/dragdrop: Use base::string16 now that string16 was moved into base namespace.

ui/base/dragdrop/cocoa_dnd_util.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.
 
 #import "ui/base/dragdrop/cocoa_dnd_util.h"
 
 #include "base/logging.h"
 #include "base/strings/sys_string_conversions.h"
 #include "googleurl/src/gurl.h"
 #import "third_party/mozilla/NSPasteboard+Utils.h"
 
 namespace ui {
 
 NSString* const kChromeDragDummyPboardType = @"org.chromium.drag-dummy-type";
 
 NSString* const kChromeDragImageHTMLPboardType = @"org.chromium.image-html";
 
 BOOL PopulateURLAndTitleFromPasteboard(GURL* url,
-                                       string16* title,
+                                       base::string16* title,
                                        NSPasteboard* pboard,
                                        BOOL convert_filenames) {
   CHECK(url);
 
   // Bail out early if there's no URL data.
   if (![pboard containsURLData])
     return NO;
 
   // -getURLs:andTitles:convertingFilenames: will already validate URIs so we
   // don't need to again. The arrays returned are both of NSStrings.
@@ skipping 14 matching lines @@
       *url = GURL(utf8_url);
       // Extra paranoia check.
       if (title && [title_array count])
         *title = base::SysNSStringToUTF16([title_array objectAtIndex:0]);
     }
   }
   return YES;
 }
 
 }  // namespace ui