Add callers and callees to profiler output

runtime/bin/vmservice/client/lib/src/observatory/view_model.dart

Index: runtime/bin/vmservice/client/lib/src/observatory/view_model.dart
diff --git a/runtime/bin/vmservice/client/lib/src/observatory/view_model.dart b/runtime/bin/vmservice/client/lib/src/observatory/view_model.dart
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index 0000000000000000000000000000000000000000..1d761784652a096230b1cac2d4973c90ed063e68
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+++ b/runtime/bin/vmservice/client/lib/src/observatory/view_model.dart
@@ -0,0 +1,108 @@
+// 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 observatory;
+
+abstract class TableTreeRow {
+  final TableTreeRow parent;
+  final int depth;
+  final List<TableTreeRow> children = new List<TableTreeRow>();
+  final List<String> columns = [];
+
+  TableTreeRow(TableTreeRow parent) :
+      parent = parent,
+      depth = parent != null ? parent.depth+1 : 0;
+
+  bool _expanded = false;
+  bool get expanded => _expanded;
+  set expanded(bool expanded) {
+    var changed = _expanded != expanded;
+    _expanded = expanded;
+    if (changed) {
+      // If the state has changed, fire callbacks.
+      if (_expanded) {
+        onShow();
+      } else {
+        onHide();
+      }
+    }
+  }
+
+  bool toggle() {
+    expanded = !expanded;
+    return expanded;
+  }
+
+  /// Fired when the tree row is expanded. Add children rows here.
+  void onShow();
+
+  /// Fired when the tree row is collapsed.
+  void onHide();
+}
+
+class TableTree {
+  final List<String> columnHeaders = [];
+  final List<TableTreeRow> rows = toObservable([]);
+
+  /// Create a table tree with column [headers].
+  TableTree(List<String> headers) {
+    columnHeaders.addAll(headers);
+  }
+
+  /// Initialize the table tree with the list of root children.
+  void initialize(List<TableTreeRow> children) {
+    rows.clear();
+    rows.addAll(children);
+  }
+
+  /// Toggle expansion of row at [rowIndex].
+  void toggle(int rowIndex) {
+    assert(rowIndex >= 0);
+    assert(rowIndex < rows.length);
+    var row = rows[rowIndex];
+    if (row.toggle()) {
+      _expand(row);
+    } else {
+      _collapse(row);
+    }
+  }
+
+  int _index(TableTreeRow row) => rows.indexOf(row);
+
+  void _insertRow(int index, TableTreeRow row) {
+    if (index == -1) {
+      rows.add(row);
+    } else {
+      rows.insert(index, row);
+    }
+  }
+
+  void _expand(TableTreeRow row) {
+    int index = _index(row);
+    assert(index != -1);
+    for (var i = 0; i < row.children.length; i++) {
+      _insertRow(index + i + 1, row.children[i]);
+    }
+  }
+
+  void _collapse(TableTreeRow row) {
+    var childCount = row.children.length;
+    if (childCount == 0) {
+      return;
+    }
+    for (var i = 0; i < childCount; i++) {
+      // Close all inner rows.
+      if (row.children[i].expanded) {
+        _collapse(row.children[i]);
+      }
+    }
+    // Collapse this row.
+    row.expanded = false;
+    // Remove all children.
+    int index = _index(row);
+    for (var i = 0; i < childCount; i++) {
+      rows.removeAt(index + 1);
+    }
+  }
+}