Add Function based profile tree

runtime/observatory/lib/src/app/view_model.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of app;
 
 abstract class TableTreeRow extends Observable {
   static const arrowRight = '\u2192';
   static const arrowDownRight = '\u21b3';
   // Number of pixels each subtree is indented.
@@ skipping 47 matching lines @@
   }
 
   void _buildRow() {
     _tr = new TableRowElement();
     for (var i = 0; i < tree.columnCount; i++) {
       var cell = _tr.insertCell(-1);
       cell.classes.add(_backgroundColorClassForRow());
       tableColumns.add(cell);
     }
     var firstColumn = tableColumns[0];
+    var columnContainer = new DivElement();
+    columnContainer.classes.add('flex-row');
     _expander = new SpanElement();
     _expander.style.display = 'inline-block';
     _expander.style.minWidth = '1.5em';
     _expander.onClick.listen(onClick);
-    firstColumn.children.add(_expander);
+    columnContainer.children.add(_expander);
     firstColumn.style.paddingLeft = '${depth * subtreeIndent}px';
+    firstColumn.children.add(columnContainer);
     updateExpanderView();
   }
 
   void updateExpanderView() {
     if (_expander == null) {
       return;
     }
     if (!hasChildren()) {
       _expander.style.visibility = 'hidden';
       _expander.style.cursor = 'auto';
@@ skipping 44 matching lines @@
 }
 
 class TableTree extends Observable {
   final TableSectionElement tableBody;
   final List<TableTreeRow> rows = [];
   final int columnCount;
 
   /// Create a table tree with column [headers].
   TableTree(this.tableBody, this.columnCount);
 
+  void clear() {
+    tableBody.children.clear();
+    rows.clear();
+  }
+
   /// Initialize the table tree with the list of root children.
   void initialize(TableTreeRow root) {
-    tableBody.children.clear();
-    rows.clear();
+    clear();
     root.onShow();
     rows.addAll(root.children);
     for (var i = 0; i < rows.length; i++) {
       rows[i].onShow();
       tableBody.children.add(rows[i].tr);
     }
   }
 
   /// Toggle expansion of row in tree.
   void toggle(TableTreeRow row) {
@@ skipping 88 matching lines @@
     return b.compareTo(a);
   }
 
   int _sortFuncAscending(int i, int j) {
     var a = getSortKeyFor(i, _sortColumnIndex);
     var b = getSortKeyFor(j, _sortColumnIndex);
     return a.compareTo(b);
   }
 
   void sort() {
-    Stopwatch sw = new Stopwatch()..start();
     assert(_sortColumnIndex >= 0);
     assert(_sortColumnIndex < columns.length);
     if (_sortDescending) {
       sortedRows.sort(_sortFuncDescending);
     } else {
       sortedRows.sort(_sortFuncAscending);
     }
   }
 
   void clearRows() {
@@ skipping 22 matching lines @@
     if (column != _sortColumnIndex) {
       return columns[column].label + '\u2003';
     }
     return columns[column].label + (_sortDescending ? arrowUp : arrowDown);
   }
 
   dynamic getValue(int row, int column) {
     return rows[row].values[column];
   }
 }