Add CombinedDesktopMediaList class

chrome/browser/media/desktop_media_list_observer.h

Index: chrome/browser/media/desktop_media_list_observer.h
diff --git a/chrome/browser/media/desktop_media_list_observer.h b/chrome/browser/media/desktop_media_list_observer.h
index 1988f52b5bca12547775721e99089833ae868162..92b809d2f7dd2766523f71c1f3071b699170d624 100644
--- a/chrome/browser/media/desktop_media_list_observer.h
+++ b/chrome/browser/media/desktop_media_list_observer.h
@@ -5,15 +5,19 @@
 #ifndef CHROME_BROWSER_MEDIA_DESKTOP_MEDIA_LIST_OBSERVER_H_
 #define CHROME_BROWSER_MEDIA_DESKTOP_MEDIA_LIST_OBSERVER_H_
 
+class DesktopMediaList;
+
 // Interface implemented by the desktop media picker dialog to receive
 // notifications about changes in DesktopMediaList.
 class DesktopMediaListObserver {
  public:
-  virtual void OnSourceAdded(int index) = 0;
-  virtual void OnSourceRemoved(int index) = 0;
-  virtual void OnSourceMoved(int old_index, int new_index) = 0;
-  virtual void OnSourceNameChanged(int index) = 0;
-  virtual void OnSourceThumbnailChanged(int index) = 0;
+  virtual void OnSourceAdded(DesktopMediaList* list, int index) = 0;
+  virtual void OnSourceRemoved(DesktopMediaList* list, int index) = 0;
+  virtual void OnSourceMoved(DesktopMediaList* list,
+                             int old_index,
+                             int new_index) = 0;
+  virtual void OnSourceNameChanged(DesktopMediaList* list, int index) = 0;
+  virtual void OnSourceThumbnailChanged(DesktopMediaList* list, int index) = 0;
 
  protected:
   virtual ~DesktopMediaListObserver() {}