Drop down the recursion limit on SanityCheckParentPointers.
Drop down the recursion limit on SanityCheckParentPointers.

This caused an unexplained sigsegv in SanityCheckParentPointers on a
test file that parses into a DOM tree 27,500 nodes deep, and dropping
the recursion limit seems to fix it in all clients.
-------------
Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=58939249

luoxn28/gumbo-parser,urandu/gumbo-parser,luoxn28/gumbo-parser,kevinhendricks/gumbo-parser,luoxn28/gumbo-parser,aleksandaratanasov/gumbo-parser,kevinhendricks/gumbo-parser,mcanthony/gumbo-parser,f123h456/gumbo-parser,f123h456/gumbo-parser,lvchao0428/gumbo-parser,vmg/gumbo-parser,Sigil-Ebook/sigil-gumbo,kevinhendricks/gumbo-parser,lvchao0428/gumbo-parser,abc00/gumbo-parser,aleksandaratanasov/gumbo-parser,vmg/gumbo-parser,mcanthony/gumbo-parser,abc00/gumbo-parser,f123h456/gumbo-parser,kevinhendricks/gumbo-parser,f123h456/gumbo-parser,urandu/gumbo-parser,vmg/gumbo-parser,google/gumbo-parser,google/gumbo-parser,mcanthony/gumbo-parser,mcanthony/gumbo-parser,f123h456/gumbo-parser,luoxn28/gumbo-parser,lvchao0428/gumbo-parser,lvchao0428/gumbo-parser,google/gumbo-parser,urandu/gumbo-parser,abc00/gumbo-parser,kevinhendricks/gumbo-parser,luoxn28/gumbo-parser,Sigil-Ebook/sigil-gumbo,lvchao0428/gumbo-parser,google/gumbo-parser,Sigil-Ebook/sigil-gumbo,google/gumbo-parser,vmg/gumbo-parser,mcanthony/gumbo-parser,aleksandaratanasov/gumbo-parser,aleksandaratanasov/gumbo-parser,abc00/gumbo-parser,Sigil-Ebook/sigil-gumbo,Sigil-Ebook/sigil-gumbo,abc00/gumbo-parser,urandu/gumbo-parser,urandu/gumbo-parser,aleksandaratanasov/gumbo-parser