Implement Desktop Media Picker (Mac version) for Desktop Capture API

chrome/browser/media/desktop_media_picker_model.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_MEDIA_DESKTOP_MEDIA_PICKER_MODEL_H_
 #define CHROME_BROWSER_MEDIA_DESKTOP_MEDIA_PICKER_MODEL_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 53 matching lines @@
   // Sets size to which the thumbnails should be scaled. If called after
   // StartUpdating() then some thumbnails may be still scaled to the old size
   // until they are updated.
   void SetThumbnailSize(const gfx::Size& thumbnail_size);
 
   // Starts updating the model. The model is initially empty, so OnSourceAdded()
   // notifications will be generated for each existing source as it is
   // enumerated. After the initial enumeration the model will be refreshed based
   // on the update period, and notifications generated only for changes in the
   // model.
-  void StartUpdating(Observer* observer);
+  virtual void StartUpdating(Observer* observer);
 
   int source_count() const { return sources_.size(); }
   const Source& source(int index) const { return sources_.at(index); }
 
+ protected:
+  // Current list of sources.
+  std::vector<Source> sources_;
+
  private:
   class Worker;
   friend class Worker;
 
   // Struct used to represent sources list the model gets from the Worker.
   struct SourceDescription {
     SourceDescription(content::DesktopMediaID id, const string16& name);
 
     content::DesktopMediaID id;
     string16 name;
@@ skipping 28 matching lines @@
   Observer* observer_;
 
   // Task runner used for the |worker_|.
   scoped_refptr<base::SequencedTaskRunner> capture_task_runner_;
 
   // An object that does all the work of getting list of sources on a background
   // thread (see |capture_task_runner_|). Destroyed on |capture_task_runner_|
   // after the model is destroyed.
   scoped_ptr<Worker> worker_;
 
-  // Current list of sources.
-  std::vector<Source> sources_;
-
   base::WeakPtrFactory<DesktopMediaPickerModel> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DesktopMediaPickerModel);
 };
 
 #endif  // CHROME_BROWSER_MEDIA_DESKTOP_MEDIA_PICKER_MODEL_H_