Added some more sequence checks in /policy/

* Added missed sequence checks to classes that were already partially
  covered with them:
  CombinedSchemaRegistry,
  ComponentCloudPolicyService,
  ComponentCloudPolicyStore,
  ConfigDirPolicyLoader,
  ForwardingSchemaRegistry,
  SchemaRegistry;
* Added new sequence checks to classes that didn't have them at all:
  CloudExternalDataManagerBase::Backend,
  ComponentCloudPolicyService::Backend;
* Some C++11 clean-up.

Bug: chromium:727645
Change-Id: I34498fbab575587757aecd7f81da6f847ed8eb08
Reviewed-on: https://chromium-review.googlesource.com/558408
Commit-Queue: Maksim Ivanov <emaxx@chromium.org>
Reviewed-by: Ivan Ĺ andrk <isandrk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#484014}

CrOS-Libchrome-Original-Commit: aef0ea84b8dacfd9b642002f7ff11956d298cd29
8 files changed
tree: afd9f64caca92bbbcfede3b4361a024ff129405f
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/