Views:: Make Labels support text selection.

ui/views/selection_controller.h

Index: ui/views/selection_controller.h
diff --git a/ui/views/selection_controller.h b/ui/views/selection_controller.h
index fe164338180ab747c1ded9e5be00ba3000b3ebf2..3837fc25a1876a8f20d7ef70ee2f504a85303cf9 100644
--- a/ui/views/selection_controller.h
+++ b/ui/views/selection_controller.h
@@ -92,6 +92,8 @@ class VIEWS_EXPORT SelectionController::Delegate {
 
   // Returns true if the associated text view is read only.
   virtual bool IsReadOnly() const = 0;
+  // Returns whether the associated view supports drag-and-drop.
+  virtual bool SupportsDrag() const = 0;
   // Returns whether there is a drag operation originating from the associated
   // view.
   virtual bool HasTextBeingDragged() const = 0;