Move initiator_csp from ResourceRequest to WebNavigationInfo

This field is used for initiating navigation, there is no need
to abuse ResourceRequest for that.

Bug: none
Change-Id: I2705e6b85a164467bf20880637b3b3271b1b9697
Reviewed-on: https://chromium-review.googlesource.com/c/1423928
Reviewed-by: Nate Chapin <japhet@chromium.org>
Commit-Queue: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#625020}
13 files changed