Prefix string16 with base:: in ui/.

ui/views/controls/tree/tree_view_unittest.cc

Index: ui/views/controls/tree/tree_view_unittest.cc
diff --git a/ui/views/controls/tree/tree_view_unittest.cc b/ui/views/controls/tree/tree_view_unittest.cc
index 1864ff9a9bfd01a76bd6e55ecb4a6fec1a17cf8e..ba89f690ec96280da12f667260f0c01e0821ea13 100644
--- a/ui/views/controls/tree/tree_view_unittest.cc
+++ b/ui/views/controls/tree/tree_view_unittest.cc
@@ -68,7 +68,7 @@ class TreeViewTest : public ViewsTestBase {
  private:
   std::string InternalNodeAsString(TreeView::InternalNode* node);
 
-  TestNode* GetNodeByTitleImpl(TestNode* node, const string16& title);
+  TestNode* GetNodeByTitleImpl(TestNode* node, const base::string16& title);
 
   DISALLOW_COPY_AND_ASSIGN(TreeViewTest);
 };
@@ -118,7 +118,7 @@ int TreeViewTest::GetRowCount() {
 }
 
 TestNode* TreeViewTest::GetNodeByTitleImpl(TestNode* node,
-                                           const string16& title) {
+                                           const base::string16& title) {
   if (node->GetTitle() == title)
     return node;
   for (int i = 0; i < node->child_count(); ++i) {