Jump to the next outer column when an inner column is too short.

third_party/WebKit/Source/core/layout/LayoutFlowThread.h

Index: third_party/WebKit/Source/core/layout/LayoutFlowThread.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutFlowThread.h b/third_party/WebKit/Source/core/layout/LayoutFlowThread.h
index 7883a0b1f8a06c4df2bf67cf2977ea0207a1dd7a..80c516a9b209278dba7455e785dabd59fca4430c 100644
--- a/third_party/WebKit/Source/core/layout/LayoutFlowThread.h
+++ b/third_party/WebKit/Source/core/layout/LayoutFlowThread.h
@@ -89,6 +89,13 @@ public:
 
     virtual void contentWasLaidOut(LayoutUnit logicalTopInFlowThreadAfterPagination) = 0;
 
+    // Find and return the next logical top after |flowThreadOffset| that can fit unbreakable
+    // content as tall as |contentLogicalHeight|. |flowThreadOffset| is expected to be at the exact
+    // top of a column. This method is called when the current column is too short to fit the
+    // content, in the hope that there exists one that's tall enough further ahead. If no such
+    // column can be found, |flowThreadOffset| will be returned.
+    LayoutUnit nextLogicalTopForUnbreakableContent(LayoutUnit flowThreadOffset, LayoutUnit contentLogicalHeight) const;
+
     virtual bool isPageLogicalHeightKnown() const { return true; }
     bool pageLogicalSizeChanged() const { return m_pageLogicalSizeChanged; }