Deprecate more old filepath functions.

chrome/browser/download/save_package.cc

 // 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.
 
 #include "chrome/browser/download/save_package.h"
 
 #include "app/l10n_util.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/i18n/file_util_icu.h"
@@ skipping 1066 matching lines @@
     name_with_proper_ext = EnsureHtmlExtension(name_with_proper_ext);
 
   FilePath::StringType file_name = name_with_proper_ext.value();
   file_util::ReplaceIllegalCharactersInPath(&file_name, ' ');
   return FilePath(file_name);
 }
 
 FilePath SavePackage::EnsureHtmlExtension(const FilePath& name) {
   // If the file name doesn't have an extension suitable for HTML files,
   // append one.
-  FilePath::StringType ext = file_util::GetFileExtensionFromPath(name);
+  FilePath::StringType ext = name.Extension();
+  if (!ext.empty())
+    ext.erase(ext.begin());  // Erase preceding '.'.
   std::string mime_type;
   if (!net::GetMimeTypeFromExtension(ext, &mime_type) ||
       !CanSaveAsComplete(mime_type)) {
     return FilePath(name.value() + FILE_PATH_LITERAL(".") +
                     kDefaultHtmlExtension);
   }
   return name;
 }
 
 FilePath SavePackage::EnsureMimeExtension(const FilePath& name,
@@ skipping 258 matching lines @@
                                int index, void* params) {
   SavePackageParam* save_params = reinterpret_cast<SavePackageParam*>(params);
   ContinueSave(save_params, path, index);
   delete save_params;
 }
 
 void SavePackage::FileSelectionCanceled(void* params) {
   SavePackageParam* save_params = reinterpret_cast<SavePackageParam*>(params);
   delete save_params;
 }