Use a direct include of strings headers in ui/, part 2.

ui/base/models/tree_node_model_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/base/models/tree_node_model.h"
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/string16.h"
-#include "base/stringprintf.h"
+#include "base/strings/string16.h"
+#include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace ui {
 
 class TreeNodeModelTest : public testing::Test, public TreeModelObserver {
  public:
   TreeNodeModelTest()
       : added_count_(0),
         removed_count_(0),
@@ skipping 290 matching lines @@
 TEST_F(TreeNodeModelTest, IsRoot) {
   TestNode root;
   EXPECT_TRUE(root.is_root());
 
   TestNode* child1 = new TestNode;
   root.Add(child1, root.child_count());
   EXPECT_FALSE(child1->is_root());
 }
 
 }  // namespace ui