Modified the pepper file chooser API to support filtering files by extensions.

chrome/browser/file_select_helper.h

 // 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.
 
 #ifndef CHROME_BROWSER_FILE_SELECT_HELPER_H_
 #define CHROME_BROWSER_FILE_SELECT_HELPER_H_
 #pragma once
 
 #include <map>
 #include <vector>
@@ skipping 105 matching lines @@
       const net::DirectoryLister::DirectoryListerData& data);
   virtual void OnListDone(int id, int error);
 
   // Cleans up and releases this instance. This must be called after the last
   // callback is received from the enumeration code.
   void EnumerateDirectoryEnd();
 
   // Helper method to get allowed extensions for select file dialog from
   // the specified accept types as defined in the spec:
   //   http://whatwg.org/html/number-state.html#attr-input-accept
-  // |accept_types| contains only valid lowercased MIME types.
+  // |accept_types| contains only valid lowercased MIME types or file extensions
+  // beginning with a period (.).
   SelectFileDialog::FileTypeInfo* GetFileTypesFromAcceptType(
       const std::vector<string16>& accept_types);
 
   // Profile used to set/retrieve the last used directory.
   Profile* profile_;
 
   // The RenderViewHost and WebContents for the page showing a file dialog
   // (may only be one such dialog).
   content::RenderViewHost* render_view_host_;
   content::WebContents* web_contents_;
@@ skipping 11 matching lines @@
   struct ActiveDirectoryEnumeration;
   std::map<int, ActiveDirectoryEnumeration*> directory_enumerations_;
 
   // Registrar for notifications regarding our RenderViewHost.
   content::NotificationRegistrar notification_registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(FileSelectHelper);
 };
 
 #endif  // CHROME_BROWSER_FILE_SELECT_HELPER_H_