drive: Fix two instances of madness in FileBrowserEventRouter

chrome/browser/chromeos/extensions/file_browser_event_router.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_EVENT_ROUTER_H_
 #define CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_BROWSER_EVENT_ROUTER_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 16 matching lines @@
 class Profile;
 
 namespace drive {
 class DriveEntryProto;
 class DriveFileSystemInterface;
 }
 
 // Monitors changes in disk mounts, network connection state and preferences
 // affecting File Manager. Dispatches appropriate File Browser events.
 class FileBrowserEventRouter
-    : public base::RefCountedThreadSafe<FileBrowserEventRouter>,
-      public chromeos::disks::DiskMountManager::Observer,
+    : public chromeos::disks::DiskMountManager::Observer,
       public chromeos::ConnectivityStateHelperObserver,
       public chromeos::SystemKeyEventListener::ModifiersObserver,
       public drive::DriveFileSystemObserver,
       public google_apis::DriveServiceObserver {
  public:
   // Interface that should keep track of the system state in regards to system
   // suspend and resume events.
   // When the |IsResuming()| returns true, it should be able to check if a
   // removable device was present before the was system suspended.
   class SuspendStateDelegate {
    public:
     virtual ~SuspendStateDelegate() {}
 
     // Returns true if the system has recently woken up.
     virtual bool SystemIsResuming() const = 0;
     // If system is resuming, returns true if the disk was present before the
     // system suspend. Should return false if the system is not resuming.
     virtual bool DiskWasPresentBeforeSuspend(
         const chromeos::disks::DiskMountManager::Disk& disk) const = 0;
   };
 
+  explicit FileBrowserEventRouter(Profile* profile);
+  virtual ~FileBrowserEventRouter();
+
   void Shutdown();
 
   // Starts observing file system change events.
   void ObserveFileSystemEvents();
 
-  // File watch setup routines.
-  bool AddFileWatch(const base::FilePath& file_path,
+  typedef base::Callback<void(bool success)> BoolCallback;
+
+  // Adds a file watch at |local_path|, associated with |virtual_path|, for
+  // an extension with |extension_id|.
+  //
+  // |callback| will be called with true on success, or false on failure.
+  // |callback| must not be null.
+  bool AddFileWatch(const base::FilePath& local_path,

[hashimoto, 2013/04/08 11:10:26]

A method returning bool while taking BoolCallback as its argument seems
confusing.
Can we change this method's return type to 'void'?

[satorux1, 2013/04/09 01:24:38]

Done.

                     const base::FilePath& virtual_path,
-                    const std::string& extension_id);
-  void RemoveFileWatch(const base::FilePath& file_path,
+                    const std::string& extension_id,
+                    const BoolCallback& callback);
+
+  // Removes a file watch at |local_path| for an extension with |extension_id|.
+  void RemoveFileWatch(const base::FilePath& local_path,
                        const std::string& extension_id);
 
   // Mounts Drive on File browser. |callback| will be called after raising a
   // mount request event to file manager on JS-side.
   void MountDrive(const base::Closure& callback);
 
   // CrosDisksClient::Observer overrides.
   virtual void OnDiskEvent(
       chromeos::disks::DiskMountManager::DiskEvent event,
       const chromeos::disks::DiskMountManager::Disk* disk) OVERRIDE;
@@ skipping 22 matching lines @@
   virtual void OnDirectoryChanged(
       const base::FilePath& directory_path) OVERRIDE;
   virtual void OnResourceListFetched(int num_accumulated_entries) OVERRIDE;
   virtual void OnFileSystemMounted() OVERRIDE;
   virtual void OnFileSystemBeingUnmounted() OVERRIDE;
 
   // chromeos::SystemKeyEventListener::ModifiersObserver overrides.
   virtual void OnModifiersChange(int pressed_modifiers) OVERRIDE;
 
  private:
-  friend class FileBrowserPrivateAPI;
-  friend class base::RefCountedThreadSafe<FileBrowserEventRouter>;
-
   typedef std::map<std::string, int> ExtensionUsageRegistry;
 
+  // This class is used to remember what extensions are watching |virtual_path|.
   class FileWatcherExtensions {
    public:
-    FileWatcherExtensions(const base::FilePath& path,
+    FileWatcherExtensions(const base::FilePath& virtual_path,
         const std::string& extension_id,
         bool is_remote_file_system);
 
     ~FileWatcherExtensions();
 
     void AddExtension(const std::string& extension_id);
 
     void RemoveExtension(const std::string& extension_id);
 
     const ExtensionUsageRegistry& GetExtensions() const;
 
     unsigned int GetRefCount() const;
 
     const base::FilePath& GetVirtualPath() const;
 
-    bool Watch(const base::FilePath& path,
-               const base::FilePathWatcher::Callback& callback);
+    // Starts a file watch at |local_path|. |file_path_watcher| will be
+    // called when changes are notified.
+    //
+    // |callback| will be called with true, if the file watch is started
+    // |successfully, or false if failed. |callback| must not be null.
+    void Watch(const base::FilePath& local_path,
+               const base::FilePathWatcher::Callback& file_watcher_callback,
+               const BoolCallback& callback);
 
    private:
-    linked_ptr<base::FilePathWatcher> file_watcher_;
+    // Called when a FilePathWatcher is created and started.
+    // |file_path_watcher| is NULL, if the watcher wasn't started successfully.
+    void OnWatcherStarted(const BoolCallback& callback,
+                          base::FilePathWatcher* file_path_watcher);
+
+    base::FilePathWatcher* file_watcher_;
     base::FilePath local_path_;
     base::FilePath virtual_path_;
     ExtensionUsageRegistry extensions_;
     unsigned int ref_count_;
     bool is_remote_file_system_;
+
+    // Note: This should remain the last member so it'll be destroyed and
+    // invalidate the weak pointers before any other members are destroyed.
+    base::WeakPtrFactory<FileWatcherExtensions> weak_ptr_factory_;
   };
 
   typedef std::map<base::FilePath, FileWatcherExtensions*> WatcherMap;
 
-  explicit FileBrowserEventRouter(Profile* profile);
-  virtual ~FileBrowserEventRouter();
-
   // USB mount event handlers.
   void OnDiskAdded(const chromeos::disks::DiskMountManager::Disk* disk);
   void OnDiskRemoved(const chromeos::disks::DiskMountManager::Disk* disk);
   void OnDiskMounted(const chromeos::disks::DiskMountManager::Disk* disk);
   void OnDiskUnmounted(const chromeos::disks::DiskMountManager::Disk* disk);
   void OnDeviceAdded(const std::string& device_path);
   void OnDeviceRemoved(const std::string& device_path);
   void OnDeviceScanned(const std::string& device_path);
   void OnFormatStarted(const std::string& device_path, bool success);
   void OnFormatCompleted(const std::string& device_path, bool success);
@@ skipping 47 matching lines @@
   int num_remote_update_requests_;
 
   // Event router behavior depends on shift modifier status. This is designed
   // for power users.
   bool shift_pressed_;
 
   DISALLOW_COPY_AND_ASSIGN(FileBrowserEventRouter);
 };
 
 #endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_BROWSER_EVENT_ROUTER_H_