GitLab

http://crrev.com/988863002/ triggered use-after-free in ASAN because it passes
  ("#" + color_str).c_str()
to FindColor() (which takes char*), then dereferences the returned pointer, which
has been deallocated.  This is a redo of the CL that fixes the problem.

BUG=455063

Review URL: https://codereview.chromium.org/989313002

Cr-Commit-Position: refs/heads/master@{#319875}