Prefix string16 with base:: in ui/.

ui/views/controls/tree/tree_view.cc

Index: ui/views/controls/tree/tree_view.cc
diff --git a/ui/views/controls/tree/tree_view.cc b/ui/views/controls/tree/tree_view.cc
index 2c7bd55c396f4a43011c386003ad99942aca8d14..3bed127fef35df73857f525203974649b7765ba5 100644
--- a/ui/views/controls/tree/tree_view.cc
+++ b/ui/views/controls/tree/tree_view.cc
@@ -482,7 +482,7 @@ void TreeView::TreeNodeChanged(TreeModel* model, TreeModelNode* model_node) {
 }
 
 void TreeView::ContentsChanged(Textfield* sender,
-                               const string16& new_contents) {
+                               const base::string16& new_contents) {
 }
 
 bool TreeView::HandleKeyEvent(Textfield* sender,
@@ -525,7 +525,7 @@ void TreeView::SetSelectedRow(int row) {
   SetSelectedNode(GetNodeForRow(row));
 }
 
-string16 TreeView::GetTextForRow(int row) {
+base::string16 TreeView::GetTextForRow(int row) {
   return GetNodeForRow(row)->GetTitle();
 }