crbug.com/656232: A nested table header group repeats on each page.
Col 1
Col 1
Col 2
Te
xt
Te
xt
Te
xt
Te
xt
Te
xt
Ft 1
Ft 2
Col 1
Col 1
Col 2
Te
xt
Te
xt
Te
xt
Te
xt
Te
xt
Te
xt
Ft 1
Ft 2
Col 1
Col 1
Col 2
Te
xt
Te
xt
Ft 1
Ft 2