GitLab

Move Permissions registration out of the body of
ExtensionsClient::Initialize() and into the ExtensionsAPIProviders by
introducing ExtensionsAPIProvider::AddPermissionsProviders().

Have each provider register their associated permissions, and have
a common ExtensionsClient initialization step call into them in order
to trigger the registration.

Bug: 873937

Change-Id: Idfc55d0690dd8cf77f62b63650deec2ae42623a2
Reviewed-on: https://chromium-review.googlesource.com/1177181Reviewed-by: Istiaque Ahmed <lazyboy@chromium.org>
Reviewed-by: Luke Halliwell <halliwell@chromium.org>
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584788}