Revert of Don't clear pending NavigationParams until didStopLoading. (patchset #5 id:80001 of https://codereview.chromium.org/2140393002/ )

Reason for revert:
This caused a regression (https://crbug.com/631617).  We'll need to look for a safer way to clear the pending_navigation_params_ and try again.

Original issue's description:
> Don't clear pending NavigationParams until didStopLoading.
>
> Clearing them at the end of NavigateInternal causes problems when a
> ScopedPageLoadDeferrer is in use.
>
> Credit to thestig@ for the test framework changes.
>
> BUG=626838
> TEST=See bug for repro steps.
>
> Committed: https://crrev.com/275d69fc4e8af8ab4a8e7d8fe621ca5b408c134d
> Cr-Commit-Position: refs/heads/master@{#407239}

TBR=avi@chromium.org,thestig@chromium.org,csharrison@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=626838

Review-Url: https://codereview.chromium.org/2190463006
Cr-Commit-Position: refs/heads/master@{#408285}
2 files changed