Make sure there's a table header before attempting to account for its offset

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

Index: third_party/WebKit/Source/core/layout/LayoutTableSection.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutTableSection.cpp b/third_party/WebKit/Source/core/layout/LayoutTableSection.cpp
index b6b20899eb531b6e11291fbc9821b0a5d974c23b..63675b82dfaed5d8d5dcafd8c010353eaa3f441c 100644
--- a/third_party/WebKit/Source/core/layout/LayoutTableSection.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutTableSection.cpp
@@ -993,7 +993,7 @@ void LayoutTableSection::layoutRows()
                 if (paginationStrutOnRow) {
                     // If there isn't room for at least one content row on a page with a header group, then
                     // we won't repeat the header on each page.
-                    if (r == 0 && table()->sectionAbove(this) == table()->header())
+                    if (!r && table()->header() && table()->sectionAbove(this) == table()->header())
                         state.setHeightOffsetForTableHeaders(state.heightOffsetForTableHeaders() - table()->header()->logicalHeight());
                     // If we have a header group we will paint it at the top of each page, move the rows
                     // down to accomodate it.