Remove the "RequestInitiatorSiteLock" feature.

The "RequestInitiatorSiteLock" feature has been introduced in r673974
back in Q3 2019, as a way to minimize the risk of shipping
NetworkService to all the platforms.  Since NetworkService has already
shipped everywhere, let's remove the no-longer-necessary feature / kill
switch.

Bug: 979357
Change-Id: Ie83399aeb56439edbeb130d9e7365dc7fb0ef582
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2466354
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Auto-Submit: Łukasz Anforowicz <lukasza@chromium.org>
Reviewed-by: Yutaka Hirano <yhirano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816809}

services/network/public/cpp/features.cc

@@ -46,12 +46,6 @@ const base::Feature kThrottleDelayable{"ThrottleDelayable",
 const base::Feature kDelayRequestsOnMultiplexedConnections{
     "DelayRequestsOnMultiplexedConnections", base::FEATURE_ENABLED_BY_DEFAULT};
 
-// When kRequestInitiatorSiteLock is enabled, then CORB, CORP and Sec-Fetch-Site
-// will validate network::ResourceRequest::request_initiator against
-// network::mojom::URLLoaderFactoryParams::request_initiator_origin_lock.
-const base::Feature kRequestInitiatorSiteLock{"RequestInitiatorSiteLock",
-                                              base::FEATURE_ENABLED_BY_DEFAULT};
-
 // When kPauseBrowserInitiatedHeavyTrafficForP2P is enabled, then a subset of
 // the browser initiated traffic may be paused if there is at least one active
 // P2P connection and the network is estimated to be congested. This feature is

services/network/public/cpp/features.h

@@ -25,8 +25,6 @@ extern const base::Feature kThrottleDelayable;
 COMPONENT_EXPORT(NETWORK_CPP)
 extern const base::Feature kDelayRequestsOnMultiplexedConnections;
 COMPONENT_EXPORT(NETWORK_CPP)
-extern const base::Feature kRequestInitiatorSiteLock;
-COMPONENT_EXPORT(NETWORK_CPP)
 extern const base::Feature kPauseBrowserInitiatedHeavyTrafficForP2P;
 COMPONENT_EXPORT(NETWORK_CPP)
 extern const base::Feature kCORBProtectionSniffing;

services/network/public/cpp/initiator_lock_compatibility.cc

@@ -7,10 +7,8 @@
 #include <string>
 
 #include "base/containers/flat_set.h"
-#include "base/feature_list.h"
 #include "base/no_destructor.h"
 #include "net/base/registry_controlled_domains/registry_controlled_domain.h"
-#include "services/network/public/cpp/features.h"
 #include "services/network/public/cpp/resource_request.h"
 #include "services/network/public/mojom/network_context.mojom.h"
 #include "url/gurl.h"
@@ -56,9 +54,6 @@ url::Origin GetTrustworthyInitiator(
   if (!request_initiator.has_value())
     return unique_origin_fallback;
 
-  if (!base::FeatureList::IsEnabled(features::kRequestInitiatorSiteLock))
-    return request_initiator.value();
-
   InitiatorLockCompatibility initiator_compatibility =
       VerifyRequestInitiatorLock(request_initiator_origin_lock,
                                  request_initiator);