Revert of Enable 'First-Party-Only' cookies by default. (patchset #3 id:40001 of https://codereview.chromium.org/1032063002/)

Reason for revert:
Blink OWNERs would like to wait a bit before shipping: https://groups.google.com/a/chromium.org/d/msg/blink-dev/wKZBCzcNssg/nZ1CFmgddJcJ

Original issue's description:
> Enable 'First-Party-Only' cookies by default.
>
> This patch reverts https://codereview.chromium.org/940373002, and adds
> back in the ~2 lines and tests that are still relevant.
>
> BUG=459154
>
> Committed: https://crrev.com/bdd0b09b5371066ad6d6c0ef2c32f5b92595316d
> Cr-Commit-Position: refs/heads/master@{#322533}

[email protected],[email protected],[email protected]
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=459154

Review URL: https://codereview.chromium.org/1043403003

Cr-Commit-Position: refs/heads/master@{#323190}
diff --git a/net/base/layered_network_delegate.cc b/net/base/layered_network_delegate.cc
index 95e4236..9fd4973 100644
--- a/net/base/layered_network_delegate.cc
+++ b/net/base/layered_network_delegate.cc
@@ -252,6 +252,15 @@
     const GURL& first_party_for_cookies) const {
 }
 
+bool LayeredNetworkDelegate::OnFirstPartyOnlyCookieExperimentEnabled() const {
+  OnFirstPartyOnlyCookieExperimentEnabledInternal();
+  return nested_network_delegate_->FirstPartyOnlyCookieExperimentEnabled();
+}
+
+void LayeredNetworkDelegate::OnFirstPartyOnlyCookieExperimentEnabledInternal()
+    const {
+}
+
 bool LayeredNetworkDelegate::
     OnCancelURLRequestWithPolicyViolatingReferrerHeader(
         const URLRequest& request,