Add support for a virtual display on ChromeOS

content/public/browser/desktop_media_id.h

Index: content/public/browser/desktop_media_id.h
diff --git a/content/public/browser/desktop_media_id.h b/content/public/browser/desktop_media_id.h
index 639a3c8d43054299e098fa289fdf7a4e8d9bc2ab..2c4a868641f08a903aaa20429688fc96ecc64d18 100644
--- a/content/public/browser/desktop_media_id.h
+++ b/content/public/browser/desktop_media_id.h
@@ -27,6 +27,7 @@ struct CONTENT_EXPORT DesktopMediaID {
     TYPE_SCREEN,
     TYPE_WINDOW,
     TYPE_AURA_WINDOW,
+    TYPE_AURA_VIRTUAL_SCREEN,
   };
   typedef intptr_t Id;
 
@@ -35,8 +36,13 @@ struct CONTENT_EXPORT DesktopMediaID {
   // type TYPE_AURA_WINDOW that corresponds to that |window|.
   static DesktopMediaID RegisterAuraWindow(aura::Window* window);
 
+  // Register the |window| as the aura::Window backing the virtual screen.
+  static void RegisterVirtualScreenAuraWindow(aura::Window* window);
+
   // For DesktopMediaID of type TYPE_AURA_WINDOW returns the |window| that was
-  // previously registered using RegisterAuraWindow().
+  // previously registered using RegisterAuraWindow() and for
+  // TYPE_AURA_VIRTUAL_SCREEN returns the |window| that was previously
+  // registered using RegisterVirtualScreenAuraWindow().
   static aura::Window* GetAuraWindowById(const DesktopMediaID& id);
 #endif  // defined(USE_AURA)