Move most of FrameLoader::CheckCompleted() to Document
Split out the the parts that are specific to the committed Document, and
move those to a new Document::CheckCompleted(). Most current callers of
FrameLoader::CheckCompleted() will now call Document::CheckCompleted()
instead. Rename the remained of FrameLoader::CheckCompleted() to
DidFinishNavigation(), and have it handling the logic that is tied to
setting Frame::loading_ to false and firing DidStopLoading() callbacks.
BUG=
Review-Url: https://codereview.chromium.org/2809733003
Cr-Commit-Position: refs/heads/master@{#466470}
15 files changed
