Remove WebNavigationParams::cache_mode

It has no effect on the request which belongs to WebNavigationInfo struct,
and is actually issued from the browser process.

It is also read back by error pages, which compare it with BypassCache.
We never set that value in production, only in
TestWebFrameClient::CommitNavigation. This change removes all assignments
to WebNavigationParams::cache_mode, so it's easy to check.

Bug: 855189
Change-Id: Icab0af329a976edbdf869ceb442d2bb12d96cda0
Reviewed-on: https://chromium-review.googlesource.com/c/1436074
Commit-Queue: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Nate Chapin <japhet@chromium.org>
Cr-Commit-Position: refs/heads/master@{#626708}
10 files changed