Remove wstring from autocomplete.

chrome/browser/ui/cocoa/tabs/tab_strip_controller.mm

 // Copyright (c) 2010 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 "chrome/browser/ui/cocoa/tabs/tab_strip_controller.h"
 
 #import <QuartzCore/QuartzCore.h>
 
 #include <limits>
 #include <string>
@@ skipping 1735 matching lines @@
   [self openURL:&url inView:view at:point];
 }
 
 // (URLDropTargetController protocol)
 - (void)dropText:(NSString*)text inView:(NSView*)view at:(NSPoint)point {
   DCHECK_EQ(view, tabStripView_.get());
 
   // If the input is plain text, classify the input and make the URL.
   AutocompleteMatch match;
   browser_->profile()->GetAutocompleteClassifier()->Classify(
-      base::SysNSStringToWide(text),
-      std::wstring(), false, &match, NULL);
+      base::SysNSStringToUTF16(text), string16(), false, &match, NULL);
   GURL url(match.destination_url);
 
   [self openURL:&url inView:view at:point];
 }
 
 // (URLDropTargetController protocol)
 - (void)indicateDropURLsInView:(NSView*)view at:(NSPoint)point {
   DCHECK_EQ(view, tabStripView_.get());
 
   // The minimum y-coordinate at which one should consider place the arrow.
@@ skipping 126 matching lines @@
   NSInteger index = [self indexFromModelIndex:modelIndex];
   BrowserWindowController* controller =
       (BrowserWindowController*)[[switchView_ window] windowController];
   DCHECK(index >= 0);
   if (index >= 0) {
     [controller setTab:[self viewAtIndex:index] isDraggable:YES];
   }
 }
 
 @end