Move HistoryController::restore* to FrameLoader

restorScrollPositionAndViewState is left mostly intact, while
restoreDocumentState is inlined into its only callsite.

BUG=321280

Review URL: https://codereview.chromium.org/76833002

git-svn-id: svn://svn.chromium.org/blink/trunk@162395 bbb929c8-8fbe-4397-9dbb-9b2b20218538