Replace transition type tracking with on-demand calculation

This removes reliance on the callbacks from blink in
RenderFrameImpl (e.g. WillSubmitForm) to track transition type.
Instead, we can calculate it when needed based on the
WebDocumentLoader instance.

Also removes NavigationStateImpl::GetTransitionType() to avoid
misusing it.

Bug: 855189
Change-Id: I5c53f0f576cec0630c8de07b2ac902a1dffc30f9
Reviewed-on: https://chromium-review.googlesource.com/1228953
Reviewed-by: Camille Lamy <clamy@chromium.org>
Commit-Queue: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#592521}
4 files changed