Adds removable-drive listing for OS X.

chrome/browser/extensions/api/image_writer_private/removable_storage_provider.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_EXTENSIONS_API_IMAGE_WRITER_PRIVATE_REMOVABLE_STORAGE_PROVIDER_H_
 #define CHROME_BROWSER_EXTENSIONS_API_IMAGE_WRITER_PRIVATE_REMOVABLE_STORAGE_PROVIDER_H_
 
 #include "base/callback.h"
 #include "chrome/common/extensions/api/image_writer_private.h"
 #include "chrome/common/ref_counted_util.h"
 
+#if defined(OS_MACOSX)
+#include <CoreFoundation/CoreFoundation.h>
+#include <DiskArbitration/DiskArbitration.h>
+
+#include "base/mac/foundation_util.h"
+#include "base/memory/weak_ptr.h"
+#endif
+
 namespace extensions {
 
 // TODO(haven): Clean up this class to remove refcounting.  http://crbug/370590
 
-typedef RefCountedVector<linked_ptr
-  <api::image_writer_private::RemovableStorageDevice> > StorageDeviceList;
+typedef RefCountedVector<linked_ptr<
+    api::image_writer_private::RemovableStorageDevice> > StorageDeviceList;
+typedef base::Callback<void(scoped_refptr<StorageDeviceList>, bool)>
+    DeviceListReadyCallback;
 
 // Abstraction for platform specific implementations of listing removable
 // storage devices
 class RemovableStorageProvider {
  public:
-  typedef base::Callback<void(scoped_refptr<StorageDeviceList>, bool)>
-    DeviceListReadyCallback;
 
   // Gets the list of all available devices and returns it via callback.
-  static void GetAllDevices(DeviceListReadyCallback callback);
+  static void GetAllDevices(const DeviceListReadyCallback& callback);
 
   // Sets the list of devices that will be returned by GetAllDevices during
   // testing.  All calls to |GetAllDevices| will return this list until
   // |ClearDeviceListForTesting| is called.
   static void SetDeviceListForTesting(
       scoped_refptr<StorageDeviceList> device_list);
   // Clears the list of devices that is used during testing.
   static void ClearDeviceListForTesting();
 
  private:
-  // Fills the provided empty device list with the available devices.
-  static bool PopulateDeviceList(scoped_refptr<StorageDeviceList> device_list);
+  // This is the actual implementation of the logic, which will be skipped if a
+  // testing value is set.
+  static void GetAllDevicesImpl(const DeviceListReadyCallback& callback);
 };
 
+#if defined(OS_MACOSX)
+// A wrapper around the DiskArbitration state.
+//
+// Listing devices on OS X involves asynchronous callbacks through the Disk
+// Arbitration framework.  This class serves to wrap up that state and maintain
+// it while we still have outstanding calls expected.
+class DAWrapper : public base::SupportsWeakPtr<DAWrapper> {

[Robert Sesek, 2014/06/02 19:56:05]

A better name for this would be RemovableStorageProviderMac. Also, is there any
reason why it should be done within this common header, instead of a _mac.h
header?

[Drew Haven, 2014/06/03 02:03:23]

I think I originally put this here just to make it accessible from my tests, but
you're right that I should add a new header.

+ public:
+  DAWrapper();
+  virtual ~DAWrapper();
+
+  // Gets the list of all available devices and returns it via callback.
+  void GetDeviceList(const DeviceListReadyCallback& callback);
+
+  // A wrapper for DeviceListReadyCallbacks which will delete the wrapper when
+  // it is fired.
+  static void WrapperDeleter(DAWrapper* wrapper,
+                             const DeviceListReadyCallback& callback,
+                             scoped_refptr<StorageDeviceList> device_list,
+                             bool success);
+
+ private:
+  // A testing spouse.
+  friend class DAWrapperSpouse;
+
+  // Processes a disk-appeared event.  This increments |updates_pending_| and
+  // then posts a task to AddDisk.  This is so we can collect all the immediate
+  // disk-appeared events and know how many we need to process and thus when to
+  // call the callback.  Operates on the disk-description dictionary.
+  void ProcessDisk(base::ScopedCFTypeRef<CFDictionaryRef> dict);
+  // Adds a disk to the disk_list.  Decrements |updates_pending_| and triggers
+  // the callback when it reaches zero.  Operates on the disk-description
+  // dictionary.
+  void AddDisk(base::ScopedCFTypeRef<CFDictionaryRef> dict);
+  // Responds to a disk-appeared event.
+  static void DiskAppearedCallback(DADiskRef disk, void* context);
+  // Responds to a disk-disappeared event.
+  static void DiskDisappearedCallback(DADiskRef disk, void* context);
+  // Checks whether the disk description in |dict| is a valid removable device.
+  static bool DiskIsValidTarget(CFDictionaryRef dict);
+
+  int updates_pending_;
+  scoped_refptr<StorageDeviceList> device_list_;
+  DeviceListReadyCallback callback_;
+  base::ScopedCFTypeRef<DASessionRef> session_;
+
+  DISALLOW_COPY_AND_ASSIGN(DAWrapper);
+};
+
+// A testing spouse for |DAWrapper|.
+class DAWrapperSpouse {

[Robert Sesek, 2014/06/02 19:56:05]

This does not belong in a public .h file.

[Drew Haven, 2014/06/03 02:03:23]

Moved to test_utils.h

+ public:
+  explicit DAWrapperSpouse(DAWrapper* spouse);
+  virtual ~DAWrapperSpouse();
+
+  // Sets the |callback_| of the |DAWrapper|.
+  void SetCallback(const DeviceListReadyCallback& callback);
+  // Sets the current |device_list_| of the |DAWrapper|.
+  void SetDeviceList(scoped_refptr<StorageDeviceList> device_list);
+  // Triggers |ProcessDisk| on the |DAWrapper|.
+  void ProcessDisk(base::ScopedCFTypeRef<CFDictionaryRef> dict);
+  // runs |DiskIsValidTarget| on the |DAWrapper|.
+  static bool DiskIsValidTarget(CFDictionaryRef dict);
+
+ private:
+  DAWrapper* spouse_;
+};
+#endif
+
 } // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_IMAGE_WRITER_PRIVATE_REMOVABLE_STORAGE_PROVIDER_H_