Add OVERRIDE to ui::TreeModelObserver overridden methods.

BUG=None
TEST=None

R=sky@chromium.org

Review URL: http://codereview.chromium.org/7046093

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@88827 0039d316-1c4b-4281-b951-d872f2087c98
void TreeView::CreateRootItems() {
  DCHECK(model_);
  DCHECK(tree_view_);
  TreeModelNode* root = model_->GetRoot();
  if (root_shown_) {
    CreateItem(NULL, TVI_LAST, root);
  } else {
    for (int i = 0; i < model_->GetChildCount(root); ++i)
      CreateItem(NULL, TVI_LAST, model_->GetChild(root, i));
  }
}

void TreeView::CreateRootItems() {
  DCHECK(model_);
  DCHECK(tree_view_);
  TreeModelNode* root = model_->GetRoot();
  if (root_shown_) {
    CreateItem(NULL, TVI_LAST, root);
  } else {
    for (int i = 0; i < model_->GetChildCount(root); ++i)
      CreateItem(NULL, TVI_LAST, model_->GetChild(root, i));
  }
}
