Make auto margins win over baseline alignment.

--HG--
extra : rebase_source : 6585732cb0207b1e523ac7aeb130f3fe1c2e4908

Author: tabatkins

css3-flexbox/Overview.src.html

@@ -1586,8 +1586,9 @@ <h3 id='cross-sizing'>
 
 			<ol>
 				<li>
-					Collect all the flexbox items whose inline-axis is parallel to the main-axis
-					and whose 'flex-item-align' is ''baseline''.
+					Collect all the flexbox items whose inline-axis is parallel to the main-axis,
+					whose 'flex-item-align' is ''baseline'',
+					and whose cross-axis margins are both non-''auto''.
 					Find the largest of the distances between each item's baseline and its hypothetical outer cross-start edge,
 					and the largest of the distances between each item's baseline and its hypothetical outer cross-end edge,
 					and sum these two values.