Enable "Hide Extension" option when "Save Link As" on the Mac

content/browser/download/base_file_mac.cc

 // 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 "content/browser/download/base_file.h"
 
 #include "content/browser/download/file_metadata_mac.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace content {
 
 DownloadInterruptReason BaseFile::AnnotateWithSourceInformation() {
   DCHECK_CURRENTLY_ON(BrowserThread::FILE);
   DCHECK(!detached_);
 
   AddQuarantineMetadataToFile(full_path_, source_url_, referrer_url_);
   AddOriginMetadataToFile(full_path_, source_url_, referrer_url_);
+
+  // Hide the downloaded file's extension in the Finder if the user chose that
+  // option in the save panel.
+  if (hide_file_extension_) {
+    SetExtensionHiddenForFile(full_path_, true);
+  }
+
   return DOWNLOAD_INTERRUPT_REASON_NONE;
 }
 
 }  // namespace content