Need to notify the multicol machinery when floats have been laid out.

third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp

Index: third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp
index 9a0a90f993fd03c929f4d54c7b9a85bba2ee6781..fc16ae42919410f28b7c7f106eb03012e42d3541 100644
--- a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp
@@ -3737,6 +3737,8 @@ LayoutUnit LayoutBlockFlow::positionAndLayoutFloat(
   child.layoutIfNeeded();
 
   if (isPaginated) {
+    paginatedContentWasLaidOut(child.logicalBottom());
+
     // We may have to insert a break before the float.
     LayoutUnit newLogicalTopMarginEdge =
         adjustFloatLogicalTopForPagination(child, logicalTopMarginEdge);
@@ -3757,6 +3759,7 @@ LayoutUnit LayoutBlockFlow::positionAndLayoutFloat(
       if (child.isLayoutBlock())
         child.setChildNeedsLayout(MarkOnlyThis);
       child.layoutIfNeeded();
+      paginatedContentWasLaidOut(child.logicalBottom());
     }
   }