If I'm reading TH correctly, this backout didn't fix the valgrind failure, but the backout of bug 1548941 did. So this bug was not at fault, and can reland.
Bug 1548568 Comment 6 Edit History
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If I'm reading TH correctly, this backout didn't fix the valgrind failure, but the backout of bug 1548941 did. So this bug was not at fault, and can reland. Edit: https://treeherder.mozilla.org/#/jobs?repo=autoland&searchStr=linux%2Cx64%2Copt%2Cvalgrind-linux64-valgrind%2Fopt%2C%28v%29&fromchange=088d7221c75aa84d4a3ad559e50e1dc99bfd9fa1&tochange=4574274db3f95575dca7da08e16d6f20242fcb2a is the relevant range.