GitLab

This change was scripted by the ThreadChecker equivalent of https://crbug.com/676387#c8.

Noteworthy:
 *  ~NonThreadSafe() used to implicitly check, ~ThreadChecker() doesn't so explicit
    checks were added in relevant destructors to maintain status quo
 * NonThreadSafe provided a public interface for CalledOnValidThread() and protected
   for DetachFromThread(). The ThreadChecker was exposed as protected where required
   and public AssertCalledOnValidThread() methods added as appropriate.

BUG=676387
TBR=alokp,benwells

Review-Url: https://codereview.chromium.org/2910473005
Cr-Commit-Position: refs/heads/master@{#476681}