Adding UseCounter specific for extensions

Replaced Blink.UseCounter.Features by Blink.UseCounter.Extensions.Features when
URL protocol is chrome-extension://

BUG=687169

Review-Url: https://codereview.chromium.org/2796283005
Cr-Commit-Position: refs/heads/master@{#473409}


CrOS-Libchrome-Original-Commit: fc32d83f891bf73c8ce299d6813baf812907a8c8
2 files changed
tree: 0899b327770a255886c8cbe95c58a9c1a44b2a96
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/