Content of cell should avoid repeating headers when it straddles multiple pages

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

Index: third_party/WebKit/Source/core/layout/LayoutTableRow.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutTableRow.cpp b/third_party/WebKit/Source/core/layout/LayoutTableRow.cpp
index c814ba3d77ccdd886e527868f947fb241e5b862f..7a3d52dff0f42f181a4976ee78181bc3e1d1259c 100644
--- a/third_party/WebKit/Source/core/layout/LayoutTableRow.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutTableRow.cpp
@@ -312,4 +312,16 @@ void LayoutTableRow::addOverflowFromCell(const LayoutTableCell* cell) {
   addContentsVisualOverflow(cellVisualOverflowRect);
 }
 
+bool LayoutTableRow::isFirstRowInSectionAfterHeader() const {
+  // If there isn't room for at least one content row on a page after the
+  // header group, then we won't repeat the header on each page.
+  // https://drafts.csswg.org/css-tables-3/#repeated-headers reads like
+  // it wants us to drop headers on only the pages that a single row
+  // won't fit but we avoid the complexity of that reading until it
+  // is clarified. Tracked by crbug.com/675904
+  LayoutTableSection* header = table()->header();

[mstensho (USE GERRIT), 2016/12/20 11:47:00]

Might want to do an early return for rowIndex()

if (rowIndex())
  return false;

[rhogan, 2016/12/20 16:06:37]

return !rowIndex() && ..; returns just as quickly no? Or is it just about
readability?

[mstensho (USE GERRIT), 2016/12/20 16:50:36]

I was thinking that you could put it in front of the declaration of 'header'.
And THEN it would be WAAAAAAAAY faster for all rows but the first. :)

Also, slightly more readable, IMHO.

[mstensho (USE GERRIT), 2016/12/20 18:20:54]

Did you mean to address this too?

+  return !rowIndex() && header && table()->sectionAbove(section()) == header &&
+         header->getPaginationBreakability() != AllowAnyBreaks;
+}
+
 }  // namespace blink