Do not allow multiline input when naming bookmarks/folders on Mac

chrome/browser/ui/cocoa/bookmarks/bookmark_name_folder_controller.mm

 // Copyright (c) 2011 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/bookmarks/bookmark_name_folder_controller.h"
 
 #include "base/mac/mac_util.h"
 #include "base/sys_string_conversions.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/cocoa/bookmarks/bookmark_model_observer_for_cocoa.h"
@@ skipping 72 matching lines @@
         contextInfo:nil];
 }
 
 - (IBAction)cancel:(id)sender {
   [NSApp endSheet:[self window]];
 }
 
 - (IBAction)ok:(id)sender {
   NSString* name = [nameField_ stringValue];
   BookmarkModel* model = profile_->GetBookmarkModel();
+
   if (node_) {
     model->SetTitle(node_, base::SysNSStringToUTF16(name));
   } else {
     model->AddFolder(parent_,
                      newIndex_,
                      base::SysNSStringToUTF16(name));
   }
   [NSApp endSheet:[self window]];
 }
 
@@ skipping 11 matching lines @@
 
 - (void)setFolderName:(NSString*)name {
   [nameField_ setStringValue:name];
 }
 
 - (NSButton*)okButton {
   return okButton_;
 }
 
 @end  // BookmarkNameFolderController