Pass ResourceResponse and StreamHandle in CommitNavigation.

Pass ResourceResponse and StreamHandle in CommitNavigation.

Split out from https://codereview.chromium.org/519533002/.

NavigationBeforeCommitInfo is removed in favor of the already existing
ResourceResponse object. In addition, replace the stream URL with a
StreamHandle which maintains ownership. The ownership is transferred
to the UI thread, which will then maintain ownership on behalf of the renderer.

This loses navigation_request_id, so also remove the existing stub code in
NavigationRequest; that will be handled by a UI-thread NavigationURLLoader
object to hide all the IO thread business, including cancellation, from the
UI thread navigation code.

BUG=376015

Review URL: https://codereview.chromium.org/612903004

Cr-Commit-Position: refs/heads/master@{#298531}