Make popup menus line up to their baseline per the Material spec.

sky/sdk/lib/rendering/flex.dart

 // Copyright 2015 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.
 
 import 'dart:math' as math;
 
 import 'box.dart';
 import 'object.dart';
 
 class FlexBoxParentData extends BoxParentData with ContainerParentDataMixin<RenderBox> {
@@ skipping 228 matching lines @@
     );
   }
 
   double getMaxIntrinsicHeight(BoxConstraints constraints) {
     return _getIntrinsicSize(
       constraints: constraints,
       sizingDirection: FlexDirection.vertical,
       childSize: (c, innerConstraints) => c.getMaxIntrinsicHeight(innerConstraints));
   }
 
-  double getDistanceToActualBaseline(TextBaseline baseline) {
-    assert(!needsLayout);
+  double computeDistanceToActualBaseline(TextBaseline baseline) {
     if (_direction == FlexDirection.horizontal)
-      return defaultGetDistanceToHighestActualBaseline(baseline);
-    return defaultGetDistanceToFirstActualBaseline(baseline);
+      return defaultComputeDistanceToHighestActualBaseline(baseline);
+    return defaultComputeDistanceToFirstActualBaseline(baseline);
   }
 
   int _getFlex(RenderBox child) {
     assert(child.parentData is FlexBoxParentData);
     return child.parentData.flex != null ? child.parentData.flex : 0;
   }
 
   double _getCrossSize(RenderBox child) {
     return (_direction == FlexDirection.horizontal) ? child.size.height : child.size.width;
   }
@@ skipping 127 matching lines @@
   }
 
   void hitTestChildren(HitTestResult result, { Point position }) {
     defaultHitTestChildren(result, position: position);
   }
 
   void paint(PaintingCanvas canvas, Offset offset) {
     defaultPaint(canvas, offset);
   }
 }