mozilla/servo — pull request #468 by jdm (2013-05-22 18:23:25+00:00)
Title: Fix various crashes, leaks, and cycles 

By the power vested in me through the agency of gdb, massif, and valgrind, here are some changes that fix various crashes that occur when shutting down at arbitrary points, along with some honest-to-goodness shutdown leaks reported by valgrind, and the layout cycles that were causing 1gb/s memory explosions when running test_hammer_layout.html.