Column balancing support in the region based multicol implementation.

LayoutTests/fast/multicol/newmulticol/cell-shrinkback.html

Index: LayoutTests/fast/multicol/newmulticol/cell-shrinkback.html
diff --git a/LayoutTests/fast/multicol/cell-shrinkback.html b/LayoutTests/fast/multicol/newmulticol/cell-shrinkback.html
similarity index 80%
copy from LayoutTests/fast/multicol/cell-shrinkback.html
copy to LayoutTests/fast/multicol/newmulticol/cell-shrinkback.html
index b1dcf5a071003ed214b0bd539f26a73ccca1a19f..bf74672dd2a71514175169cfcce83d5ac1eb83ce 100644
--- a/LayoutTests/fast/multicol/cell-shrinkback.html
+++ b/LayoutTests/fast/multicol/newmulticol/cell-shrinkback.html
@@ -1,3 +1,7 @@
+<script>
+  if (window.internals)
+    internals.settings.setRegionBasedColumnsEnabled(true);
+</script>
 <div style="height: 100px; width: 200px; border: solid; -webkit-columns: 2; -webkit-column-gap:0">
     <div style="height: 55px;"></div>
     <table cellspacing=0 cellpadding=0>