Use unique IDs for accessibility nodes on Android

ui/accessibility/platform/ax_platform_node_win.h

Index: ui/accessibility/platform/ax_platform_node_win.h
diff --git a/ui/accessibility/platform/ax_platform_node_win.h b/ui/accessibility/platform/ax_platform_node_win.h
index 39792726b57c49ee169ad3440fd615b4eefaa1b7..eb747ed4d0b1a02aa2ff0cafb266ed53205f3f61 100644
--- a/ui/accessibility/platform/ax_platform_node_win.h
+++ b/ui/accessibility/platform/ax_platform_node_win.h
@@ -297,16 +297,6 @@ AXPlatformNodeWin
                     IA2TextBoundaryType ia2_boundary,
                     LONG start_offset,
                     ui::TextBoundaryDirection direction);
-
-  // A windows-specific unique ID for this object. It's returned in
-  // IAccessible2::get_uniqueID, but more importantly it's used for
-  // firing events. On Windows, we fire events on the nearest parent HWND
-  // and pass the unique ID as the child id parameter. When the client
-  // wants to retrieve the object the event was fired on, it calls
-  // get_accChild and passes the child ID. We use negative IDs for the unique
-  // ID so we can distinguish a request for an arbitrary child from a request
-  // for an immediate child of an object by its 0-based index.
-  LONG unique_id_win_;
 };
 
 }  // namespace ui