[Media Gallery] Added code to support mtp device media file system on Windows.

chrome/browser/media_gallery/mtp_device_delegate_impl_win.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_MEDIA_GALLERY_MTP_DEVICE_DELEGATE_IMPL_LINUX_H_
-#define CHROME_BROWSER_MEDIA_GALLERY_MTP_DEVICE_DELEGATE_IMPL_LINUX_H_
+#ifndef CHROME_BROWSER_MEDIA_GALLERY_MTP_DEVICE_DELEGATE_IMPL_WIN_H_
+#define CHROME_BROWSER_MEDIA_GALLERY_MTP_DEVICE_DELEGATE_IMPL_WIN_H_
+
+#include <PortableDeviceApi.h>
 
 #include "base/memory/ref_counted.h"
 #include "base/platform_file.h"
+#include "base/string16.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/win/scoped_comptr.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "webkit/fileapi/file_system_file_util.h"
 #include "webkit/fileapi/media/mtp_device_delegate.h"
 
 class FilePath;
 
 namespace base {
 class SequencedTaskRunner;
 }
 
 namespace chrome {
 
 // Helper class to communicate with MTP storage to complete isolated file system
 // operations. This class contains platform specific code to communicate with
 // the attached MTP storage. Instantiate this class per MTP storage.
 // This class is ref-counted, because MtpDeviceDelegate is ref-counted.
-class MtpDeviceDelegateImplLinux : public fileapi::MtpDeviceDelegate,
-                                   public content::NotificationObserver {
+class MtpDeviceDelegateImplWin : public fileapi::MtpDeviceDelegate,
+                                 public content::NotificationObserver {
  public:
   // Constructed on UI thread. Defer the device initializations until the first
   // file operation request. Do all the initializations in LazyInit() function.
-  explicit MtpDeviceDelegateImplLinux(const std::string& device_location);
+  explicit MtpDeviceDelegateImplWin(const string16& pnp_device_id);
 
   // Overridden from MtpDeviceDelegate. All the functions are called on
   // |media_task_runner_|.
   virtual base::PlatformFileError GetFileInfo(
       const FilePath& file_path,
       base::PlatformFileInfo* file_info) OVERRIDE;
   virtual fileapi::FileSystemFileUtil::AbstractFileEnumerator*
       CreateFileEnumerator(const FilePath& root, bool recursive) OVERRIDE;
   virtual base::PlatformFileError CreateSnapshotFile(
       const FilePath& device_file_path,
       const FilePath& local_path,
       base::PlatformFileInfo* file_info) OVERRIDE;
   virtual base::SequencedTaskRunner* media_task_runner() OVERRIDE;
   virtual void DeleteOnCorrectThread() const OVERRIDE;
 
  private:
   friend struct fileapi::MtpDeviceDelegateDeleter;
-  friend class base::DeleteHelper<MtpDeviceDelegateImplLinux>;
+  friend class base::DeleteHelper<MtpDeviceDelegateImplWin>;
 
   // Private because this class is ref-counted.
-  virtual ~MtpDeviceDelegateImplLinux();
+  virtual ~MtpDeviceDelegateImplWin();
 
   // content::NotificationObserver implementation.
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
   // Opens the device for communication. This function is called on
   // |media_task_runner_|. Returns true if the device is ready for
   // communication, else false.
   bool LazyInit();
 
-  // Stores the registered file system device path value. This path does not
-  // correspond to a real device path (E.g.: "/usb:2,2:81282").
-  const std::string device_path_;
+  // Stores the plug and play device ID string. This is used to open the device

[Peter Kasting, 2012/10/24 22:51:41]

Nit: Member variables should not say "stores a" or "stores the".  (several
places)

[kmadhusu, 2012/10/25 19:12:48]

Done.

+  // for communication.
+  // (E.g.:\\?\usb#vid_04a9&pid_3073#12#{6ac27878-a6fa-4155-ba85-f98f491d4f33})

[Peter Kasting, 2012/10/24 22:51:41]

Nit: For clarity, remove the parens, add quotes, add whitespace.  Ends up like:

  // The PnP device ID, used to open the device for communication, e.g.
  // "\\?\usb#vid_04a9&pid_3073#12#{6ac27878-a6fa-4155-ba85-f98f491d4f33}".

(Same applies below)

[kmadhusu, 2012/10/25 19:12:48]

Done.

+  string16 pnp_device_id_;
 
-  // Stores the device handle returned by
-  // MediaTransferProtocolManager::OpenStorage().
-  std::string device_handle_;
+  // Stores the registered media file system path.
+  // E.g.: \\mtp:StorageSerial:SID-{10001,E,9823}:237483
+  const string16 registered_dev_path_;

[Peter Kasting, 2012/10/24 22:51:41]

Nit: Do not abbreviate "device" to "dev"

[kmadhusu, 2012/10/25 19:12:48]

Done.

+
+  // Stores the removable storage root object identifier.
+  string16 storage_object_id_;
 
   // Stores a reference to worker pool thread. All requests and response of file
   // operations are posted on |media_task_runner_|.
   scoped_refptr<base::SequencedTaskRunner> media_task_runner_;
 
-  // |media_task_runner_| can wait on this event until the requested task is
-  // complete.
-  base::WaitableEvent on_task_completed_event_;
+  // Stores a pointer to IPortableDevice interface that provides access to a
+  // portable device.

[Peter Kasting, 2012/10/24 22:51:41]

Nit: This comment mostly restates the code.  If this is the device the other
comments refer to, this could say something like "The device itself."

[kmadhusu, 2012/10/25 19:12:48]

Done.

+  base::win::ScopedComPtr<IPortableDevice> device_;
 
   // Used to notify |media_task_runner_| pending tasks about the shutdown
   // sequence.
   base::WaitableEvent on_shutdown_event_;
 
   // Handles registering notifications with the NotificationService.
   // Used to listen for application termination message.
   content::NotificationRegistrar registrar_;
 
-  DISALLOW_COPY_AND_ASSIGN(MtpDeviceDelegateImplLinux);
+  DISALLOW_COPY_AND_ASSIGN(MtpDeviceDelegateImplWin);
 };
 
 }  // namespace chrome
 
-#endif  // CHROME_BROWSER_MEDIA_GALLERY_MTP_DEVICE_DELEGATE_IMPL_LINUX_H_
+#endif  // CHROME_BROWSER_MEDIA_GALLERY_MTP_DEVICE_DELEGATE_IMPL_WIN_H_