fix build with enable_web_intents=0 on chromeos

chrome/browser/chromeos/extensions/file_browser_private_api.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_CHROMEOS_EXTENSIONS_FILE_BROWSER_PRIVATE_API_H_
 #define CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_BROWSER_PRIVATE_API_H_
 
 #include <map>
 #include <queue>
 #include <string>
@@ skipping 180 matching lines @@
                              const std::set<std::string>& available_apps,
                              std::set<std::string>* default_apps);
 
   // Find the list of drive apps that can be used with the given file types. If
   // a default task is set in the result list, then |default_already_set| is set
   // to true.
   bool FindDriveAppTasks(const FileInfoList& file_info_list,
                          ListValue* result_list,
                          bool* default_already_set);
 
+#if defined(ENABLE_WEB_INTENTS)
   // Find the list of Web Intent tasks that can be used with the given file
   // types, appending them to the |result_list|.
   bool FindWebIntentTasks(const std::vector<FilePath>& file_paths,
                           ListValue* result_list);
+#endif
 
   // Find the list of app file handlers that can be used with the given file
   // types, appending them to the |result_list|.
   bool FindAppTasks(const std::vector<FilePath>& file_paths,
                     ListValue* result_list);
 };
 
 // Implements the chrome.fileBrowserPrivate.executeTask method.
 class ExecuteTasksFileBrowserFunction : public AsyncExtensionFunction {
  public:
@@ skipping 634 matching lines @@
  protected:
   virtual ~ValidatePathNameLengthFunction();
 
   void OnFilePathLimitRetrieved(size_t current_length, size_t max_length);
 
   // AsyncExtensionFunction overrides.
   virtual bool RunImpl() OVERRIDE;
 };
 
 #endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_BROWSER_PRIVATE_API_H_