Avoid conversion of index to BookmarkNode pointer unnacessarily.

components/bookmarks/browser/bookmark_expanded_state_tracker_unittest.cc

 // Copyright 2014 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 "components/bookmarks/browser/bookmark_expanded_state_tracker.h"
 
 #include "base/files/file_path.h"
 #include "base/message_loop/message_loop.h"
 #include "base/prefs/pref_service.h"
 #include "base/prefs/pref_service_factory.h"
@@ skipping 70 matching lines @@
   EXPECT_EQ(nodes, tracker->GetExpandedNodes());
 
   // Add a folder and mark it expanded.
   const BookmarkNode* n1 = model_->AddFolder(
       model_->bookmark_bar_node(), 0, base::ASCIIToUTF16("x"));
   nodes.insert(n1);
   tracker->SetExpandedNodes(nodes);
   EXPECT_EQ(nodes, tracker->GetExpandedNodes());
 
   // Remove the folder, which should remove it from the list of expanded nodes.
-  model_->Remove(model_->bookmark_bar_node(), 0);
+  model_->Remove(model_->bookmark_bar_node(),
+                 model_->bookmark_bar_node()->GetChild(0));
   nodes.erase(n1);
   n1 = NULL;
   EXPECT_EQ(nodes, tracker->GetExpandedNodes());
 }
 
 TEST_F(BookmarkExpandedStateTrackerTest, RemoveAllUserBookmarks) {
   BookmarkExpandedStateTracker* tracker = model_->expanded_state_tracker();
 
   // Add a folder and mark it expanded.
   const BookmarkNode* n1 = model_->AddFolder(
       model_->bookmark_bar_node(), 0, base::ASCIIToUTF16("x"));
   BookmarkExpandedStateTracker::Nodes nodes;
   nodes.insert(n1);
   tracker->SetExpandedNodes(nodes);
   // Verify that the node is present.
   EXPECT_EQ(nodes, tracker->GetExpandedNodes());
   // Call remove all.
   model_->RemoveAllUserBookmarks();
   // Verify node is not present.
   EXPECT_TRUE(tracker->GetExpandedNodes().empty());
 }
 
 }  // namespace bookmarks