[fsp] Simplify ID of provided file systems.

chrome/browser/chromeos/file_system_provider/service.h

 // Copyright 2014 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_FILE_SYSTEM_PROVIDER_SERVICE_H_
 #define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_SERVICE_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 10 matching lines @@
 
 class ServiceFactory;
 
 // Manages and registers the fileSystemProvider service.
 class Service : public KeyedService {
  public:
   explicit Service(Profile* profile);
   virtual ~Service();
 
   // Registers a file system provided by an extension with the |extension_id|.
-  // For success, it returns a file system id, which is of the following format:
-  // |extension_id|-unique-hash, where unique is an auto-incremented non-zero
-  // number, and hash is the user profile hash.
-  // For failures, it returns an empty string.
-  std::string RegisterFileSystem(const std::string& extension_id,
-                                 const std::string& file_system_name);
+  // For success, it returns a numeric file system id, which is an
+  // auto-incremented non-zero value. For failures, it returns zero.
+  int RegisterFileSystem(const std::string& extension_id,
+                         const std::string& file_system_name);
 
   // Unregisters a file system with the specified |file_system_id| for the
   // |extension_id|. For success returns true, otherwise false.
   bool UnregisterFileSystem(const std::string& extension_id,
-                            const std::string& file_system_id);
+                            int file_system_id);
 
   // Returns a list of currently registered file systems. All items are copied.
   std::vector<ProvidedFileSystem> GetRegisteredFileSystems();
 
   // Adds and removes observers.
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 
   // Gets the singleton instance for the |context|.
   static Service* Get(content::BrowserContext* context);
 
  private:
-  typedef std::map<std::string, ProvidedFileSystem> FileSystemMap;
+  typedef std::map<int, ProvidedFileSystem> FileSystemMap;
 
   Profile* profile_;
   ObserverList<Observer> observers_;
   FileSystemMap file_systems_;
-  int next_handle_;
+  int next_id_;
 
   DISALLOW_COPY_AND_ASSIGN(Service);
 };
 
 }  // namespace file_system_provider
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_SERVICE_H_