Stop setting invalid value to the |tab_id| field of fileBrowserHandler API.

chrome/browser/chromeos/file_manager/file_tasks.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.
 //
 // This file provides utility functions for "file tasks".
 //
 // WHAT ARE FILE TASKS?
 //
 // File tasks are representatiosn of actions that can be performed over the
 // currently selected files from Files.app. A task can be either of:
@@ skipping 219 matching lines @@
 
 // Executes file handler task for each element of |file_urls|.
 // Returns |false| if the execution cannot be initiated. Otherwise returns
 // |true| and then eventually calls |done| when all the files have been handled.
 // |done| can be a null callback.
 //
 // Parameters:
 // profile    - The profile used for making this function call.
 // app_id     - The ID of the app requesting the file task execution.
 // source_url - The source URL which originates this function call.
-// tab_id     - The ID of the tab which originates this function call.
-//              This can be 0 if no tab is associated.
 // task       - See the comment at TaskDescriptor struct.
 // file_urls  - URLs of the target files.
 // done       - The callback which will be called on completion.
 //              The callback won't be called if the function returns
 //              false.
 bool ExecuteFileTask(Profile* profile,
                      const GURL& source_url,
                      const std::string& app_id,
-                     int32 tab_id,
                      const TaskDescriptor& task,
                      const std::vector<fileapi::FileSystemURL>& file_urls,
                      const FileTaskFinishedCallback& done);
 
 typedef extensions::app_file_handler_util::PathAndMimeTypeSet
     PathAndMimeTypeSet;
 
 // Finds the Drive app tasks that can be used with the given |path_mime_set|
 // from |drive_app_registry|, and append them to the |result_list|.
 // Drive app tasks will be found only if all of the files are on Drive.
@@ skipping 38 matching lines @@
 // task is found (i.e. the default task may not exist in |tasks|). No tasks
 // should be set as default before calling this function.
 void ChooseAndSetDefaultTask(const PrefService& pref_service,
                              const PathAndMimeTypeSet& path_mime_set,
                              std::vector<FullTaskDescriptor>* tasks);
 
 }  // namespace file_tasks
 }  // namespace file_manager
 
 #endif  // CHROME_BROWSER_CHROMEOS_FILE_MANAGER_FILE_TASKS_H_