Pass DocumentLoader to FrameLoader::CommitDocumentLoader

This CL allows FrameLoader::CommitDocumentLoader to commit a specified
DocumentLoader instead of the provisional DocumentLoader. This is part
of a series of CLs that aim at removing the provisional loader (step 8k
in the linked doc in the bug).

Bug: 855189
Change-Id: Ic59f1793c1db01d4a6f05546a67ce42ec5f70cd3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1611818
Commit-Queue: Camille Lamy <clamy@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#676871}
2 files changed