Removing NavigationRequest::TakeNavigationHandle.

This function is unused since the NavigationHandle and NavigationRequest
are kept together now.

Change-Id: I0ca24dc4dd37712c298084f7c2d2088df9a24e3c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1495547
Reviewed-by: Camille Lamy <clamy@chromium.org>
Commit-Queue: Arthur Hemery <ahemery@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638219}
2 files changed