Fix FreeList::zapFreedMemory to fail "use-of-uninitialized-value" on MSAN

A CL for fallback font collection[1] broke MSAN bots[2] and was reverted.

Another try to fix[2] also fails on MSAN bots at
FreeList::zapFreeMemory[3]. This patch allows zapFreeMemory to write to
uninitialized memory.

[1] https://codereview.chromium.org/1241613006/
[2] https://codereview.chromium.org/1244973003/
[3] http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_msan_rel_ng/builds/84

BUG=514099

Review URL: https://codereview.chromium.org/1259893002

git-svn-id: svn://svn.chromium.org/blink/trunk@199701 bbb929c8-8fbe-4397-9dbb-9b2b20218538
3 files changed
tree: b86ed14e2d9cf3c473d5e91e392b8caf5fe3e518
  1. third_party/