memory-infra: Avoid dereferencing polling_state_ when it could be null

BUG=706023

Review-Url: https://codereview.chromium.org/2787533002
Cr-Commit-Position: refs/heads/master@{#460736}


CrOS-Libchrome-Original-Commit: 3d723ac3847809a99d6e46da60b297a0eb816c88
1 file changed
tree: 1b462cf5f9f23c2e11bdcc4d98bd4490322f9824
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/