Add a data source field for volumes.

chrome/browser/chromeos/file_system_provider/registry.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_REGISTRY_H_
 #define CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_REGISTRY_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/chromeos/file_system_provider/registry_interface.h"
 #include "chrome/browser/chromeos/file_system_provider/watcher.h"
 
 class Profile;
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }  // namespace user_prefs
 
 namespace chromeos {
 namespace file_system_provider {
 
 // Key names for preferences.
 extern const char kPrefKeyFileSystemId[];
 extern const char kPrefKeyDisplayName[];
 extern const char kPrefKeyWritable[];
+extern const char kPrefKeySource[];
 extern const char kPrefKeySupportsNotifyTag[];
 extern const char kPrefKeyWatchers[];
 extern const char kPrefKeyWatcherEntryPath[];
 extern const char kPrefKeyWatcherRecursive[];
 extern const char kPrefKeyWatcherPersistentOrigins[];
 extern const char kPrefKeyWatcherLastTag[];
 extern const char kPrefKeyOpenedFilesLimit[];
 
 class ProvidedFileSystemInfo;
 
 // Registers preferences to remember registered file systems between reboots.
 void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
 
+// Converts a file system's data source value back and forth between Source and
+// std::string types.
+std::string SourceToString(Source source);
+bool StringToSource(const std::string& source, Source* result);
+
 // Remembers and restores file systems in a persistent storage.
 class Registry : public RegistryInterface {
  public:
   explicit Registry(Profile* profile);
   ~Registry() override;
 
   // RegistryInterface overrides.
   void RememberFileSystem(const ProvidedFileSystemInfo& file_system_info,
                           const Watchers& watchers) override;
   void ForgetFileSystem(const std::string& extension_id,
                         const std::string& file_system_id) override;
   scoped_ptr<RestoredFileSystems> RestoreFileSystems(
       const std::string& extension_id) override;
   void UpdateWatcherTag(const ProvidedFileSystemInfo& file_system_info,
                         const Watcher& watcher) override;
 
  private:
   Profile* profile_;  // Not owned.
   DISALLOW_COPY_AND_ASSIGN(Registry);
 };
 
 }  // namespace file_system_provider
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_FILE_SYSTEM_PROVIDER_REGISTRY_H_