Pass the NavigationRequest to NavigationController at commit time

This CL makes it so that NavigationRequests are passed to the
NavigationController at commit time instead of NavigationHandles. This
is a preparatory CL for tracking NavigationRequests in the
NavigationController and using them to make decisions about the deletion
of the pending NavigationEntry.

Bug: 803859
Change-Id: I71f48e2d8ee68c6d02d4ac6b7642137b8206febb
Reviewed-on: https://chromium-review.googlesource.com/c/1327201
Reviewed-by: Nasko Oskov <nasko@chromium.org>
Reviewed-by: Charlie Reis <creis@chromium.org>
Commit-Queue: Camille Lamy <clamy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#613977}
11 files changed