GitLab

This moves code out of //java/apps/chrome/.../precache into:
  . //components/precache/android/: classes that provide information about
    device-state, network connectivity etc.
  . //chrome/android/.../precache/: precache service and service launchers.

BUG=401552

Review URL: https://codereview.chromium.org/1031003003

Cr-Commit-Position: refs/heads/master@{#322298}