Added default implementations of GetAcceleratorForCommandId.

ui/views/examples/tree_view_example.cc

Index: ui/views/examples/tree_view_example.cc
diff --git a/ui/views/examples/tree_view_example.cc b/ui/views/examples/tree_view_example.cc
index 35a812c4200c406b103b2e8503805768c490db1c..9681ede1559422704d3ffbf79d7ca29ac13a3166 100644
--- a/ui/views/examples/tree_view_example.cc
+++ b/ui/views/examples/tree_view_example.cc
@@ -153,12 +153,6 @@ bool TreeViewExample::IsCommandIdEnabled(int command_id) const {
   return const_cast<TreeViewExample*>(this)->IsCommandIdEnabled(command_id);
 }
 
-bool TreeViewExample::GetAcceleratorForCommandId(
-    int command_id,
-    ui::Accelerator* accelerator) const {
-  return false;
-}
-
 void TreeViewExample::ExecuteCommand(int command_id, int event_flags) {
   NodeType* selected_node =
       static_cast<NodeType*>(tree_view_->GetSelectedNode());