Remove assertion in SetResourceConstraints.

BUG=312233
R=rmcilroy@chromium.org

Review URL: https://codereview.chromium.org/48303004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@17416 ce2b1a6d-e550-0410-aec6-3dcde31c8c00