Views:: Make Labels support text selection.

ui/views/selection_controller_delegate.h

Index: ui/views/selection_controller_delegate.h
diff --git a/ui/views/selection_controller_delegate.h b/ui/views/selection_controller_delegate.h
index f0b500090e648d7452043c721adafc6ec01c472c..d9c823d607d3692f527dc2d7418860ae17a5fc5c 100644
--- a/ui/views/selection_controller_delegate.h
+++ b/ui/views/selection_controller_delegate.h
@@ -24,10 +24,13 @@ class VIEWS_EXPORT SelectionControllerDelegate {
 
   // 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;
-  // Sets whether text is being dragged from the associated view.
+  // Sets whether text is being dragged from the associated view. Called only if
+  // the delegate supports drag.
   virtual void SetTextBeingDragged(bool value) = 0;
   // Returns the height of the associated view.
   virtual int GetViewHeight() const = 0;