Prevents double-clicks on a tab close button from aslo maximizing the browser

ash/wm/workspace/workspace_event_handler.h

Index: ash/wm/workspace/workspace_event_handler.h
diff --git a/ash/wm/workspace/workspace_event_handler.h b/ash/wm/workspace/workspace_event_handler.h
index 65a05ac81d78a1326d5c6a3c1269f3810cdf63f8..0a466124b1da8138dec03fb4ea01e325905926a5 100644
--- a/ash/wm/workspace/workspace_event_handler.h
+++ b/ash/wm/workspace/workspace_event_handler.h
@@ -38,6 +38,13 @@ class WorkspaceEventHandler : public ui::EventHandler {
 
   MultiWindowResizeController multi_window_resize_controller_;
 
+  // The non-client component for the target of a MouseEvent or GestureEvent.
+  // Events can be destructive to the window tree, which can cause the
+  // component of a ui::EF_IS_DOUBLE_CLICK event to no longer be the same as
+  // that of the initial click. Acting on a double click should only occur for
+  // matching components.
+  int event_target_component_;
+
   DISALLOW_COPY_AND_ASSIGN(WorkspaceEventHandler);
 };