Fix content_shell with network service enabled not loading pages.

This regressed in my earlier cl r528763.

This is a reland of r547221.

Bug: 833612

Change-Id: I4c2649414d42773f2530e1abe5912a04fcd0ed9b
Reviewed-on: https://chromium-review.googlesource.com/1064702
Reviewed-by: Jay Civelli <jcivelli@chromium.org>
Commit-Queue: John Abd-El-Malek <jam@chromium.org>
Cr-Commit-Position: refs/heads/master@{#560011}
ShellMainDelegate::ShellMainDelegate() {

ShellMainDelegate::ShellMainDelegate() {
}
