GitLab

Move ownership of the ICPMessageSender to the bindings system. This
internalizes a bit more of the logic into the ExtensionBindingsSystem,
and moves a bit more out of the overly-busy Dispatcher classes.

Bug: 653596
Change-Id: I321afadb64c8351ca95cb0953a0148c71ad7f005
Reviewed-on: https://chromium-review.googlesource.com/570932
Commit-Queue: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: Istiaque Ahmed <lazyboy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487291}