Provide a dedicated getter for the offset to a repeatable THEAD.

third_party/WebKit/Source/core/paint/TableSectionPainter.cpp

Index: third_party/WebKit/Source/core/paint/TableSectionPainter.cpp
diff --git a/third_party/WebKit/Source/core/paint/TableSectionPainter.cpp b/third_party/WebKit/Source/core/paint/TableSectionPainter.cpp
index ab17ec7349d1961d6e2450496b67448f85841734..829be97b402c4b56cad3cda5d6dddcfdaff03802 100644
--- a/third_party/WebKit/Source/core/paint/TableSectionPainter.cpp
+++ b/third_party/WebKit/Source/core/paint/TableSectionPainter.cpp
@@ -55,7 +55,7 @@ void TableSectionPainter::paintRepeatingHeaderGroup(
   // Move paginationOffset to the top of the next page.
   // The header may have a pagination strut before it so we need to account for
   // that when establishing its position.
-  LayoutUnit headerGroupOffset = table->pageLogicalOffset();
+  LayoutUnit headerGroupOffset = table->blockOffsetToFirstRepeatableHeader();
   if (LayoutTableRow* row = m_layoutTableSection.firstRow())
     headerGroupOffset += row->paginationStrut();
   LayoutUnit offsetToNextPage =