Move registerWindowFocusChangedListener out of BaseChromiumApplication

Code related to WindowFocusChanged as well as code related to tracking
activities is moved to ApplicationStatus.java

TBR=slan  # Missing one rslgtm

Bug: 560466
Cq-Include-Trybots: master.tryserver.chromium.android:android_cronet_tester;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I4efd3e3a13ce7731e5b62916086a29a7352552a2
Reviewed-on: https://chromium-review.googlesource.com/768949
Commit-Queue: agrieve <agrieve@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Reviewed-by: Ryan Sleevi <rsleevi@chromium.org>
Reviewed-by: agrieve <agrieve@chromium.org>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#519014}

CrOS-Libchrome-Original-Commit: ab3f1bd2403e0b78e7ca7c22bdb052fb71349d91
4 files changed
tree: 13a8f979e05558c41954429176000cbe3004448e
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/