Add a refresh button for providers which do not support watchers.

chrome/browser/chromeos/file_manager/volume_manager.h

 // Copyright 2013 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_MANAGER_VOLUME_MANAGER_H_
 #define CHROME_BROWSER_CHROMEOS_FILE_MANAGER_VOLUME_MANAGER_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 101 matching lines @@
   }
   MountContext mount_context() const { return mount_context_; }
   const base::FilePath& system_path_prefix() const {
     return system_path_prefix_;
   }
   const std::string& volume_label() const { return volume_label_; }
   bool is_parent() const { return is_parent_; }
   bool is_read_only() const { return is_read_only_; }
   bool has_media() const { return has_media_; }
   bool configurable() const { return configurable_; }
+  bool watchable() const { return watchable_; }
 
  private:
   Volume();
 
   // The ID of the volume.
   std::string volume_id_;
 
   // The ID for provided file systems. If other type, then empty string. Unique
   // per providing extension.
   std::string file_system_id_;
@@ skipping 44 matching lines @@
 
   // True if the volume is read only.
   bool is_read_only_;
 
   // True if the volume contains media.
   bool has_media_;
 
   // True if the volume is configurable.
   bool configurable_;
 
+  // True if the volume notifies about changes via file/directory watchers.
+  bool watchable_;
+
   DISALLOW_COPY_AND_ASSIGN(Volume);
 };
 
 // Manages "Volume"s for file manager. Here are "Volume"s.
 // - Drive File System (not yet supported).
 // - Downloads directory.
 // - Removable disks (volume will be created for each partition, not only one
 //   for a device).
 // - Mounted zip archives.
 class VolumeManager : public KeyedService,
@@ skipping 115 matching lines @@
 
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate its weak pointers before any other members are destroyed.
   base::WeakPtrFactory<VolumeManager> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(VolumeManager);
 };
 
 }  // namespace file_manager
 
 #endif  // CHROME_BROWSER_CHROMEOS_FILE_MANAGER_VOLUME_MANAGER_H_