Stop logging RequestInitiatorOriginLockCompatibility UMA.

Fixed: 1301593
Change-Id: I1d563591bce5a4d86887007cba1272b75db467ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3495903
Reviewed-by: Charles Reis <creis@chromium.org>
Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
Auto-Submit: Łukasz Anforowicz <lukasza@chromium.org>
Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
Cr-Commit-Position: refs/heads/main@{#977086}
diff --git a/content/browser/loader/cross_site_document_blocking_browsertest.cc b/content/browser/loader/cross_site_document_blocking_browsertest.cc
index 9545ed2f..cf0f49c 100644
--- a/content/browser/loader/cross_site_document_blocking_browsertest.cc
+++ b/content/browser/loader/cross_site_document_blocking_browsertest.cc
@@ -53,7 +53,6 @@
 #include "net/test/embedded_test_server/embedded_test_server.h"
 #include "services/network/public/cpp/corb/corb_impl.h"
 #include "services/network/public/cpp/features.h"
-#include "services/network/public/cpp/initiator_lock_compatibility.h"
 #include "services/network/public/cpp/network_switches.h"
 #include "services/network/test/test_url_loader_client.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ -66,8 +65,6 @@
 using testing::HasSubstr;
 using Action = network::corb::CrossOriginReadBlocking::Action;
 using CorbMimeType = network::corb::CrossOriginReadBlocking::MimeType;
-using RequestInitiatorOriginLockCompatibility =
-    network::InitiatorLockCompatibility;
 
 namespace {
 
@@ -103,10 +100,6 @@
                        const std::string& resource_name) {
   FetchHistogramsFromChildProcesses();
 
-  histograms.ExpectUniqueSample(
-      "NetworkService.URLLoader.RequestInitiatorOriginLockCompatibility",
-      network::InitiatorLockCompatibility::kCompatibleLock, 1);
-
   // No ORB-specific UMA at this point.
   if (base::FeatureList::IsEnabled(
           network::features::kOpaqueResponseBlockingV01)) {
diff --git a/services/network/cors/cors_url_loader_factory.cc b/services/network/cors/cors_url_loader_factory.cc
index 62a413f..ef36578 100644
--- a/services/network/cors/cors_url_loader_factory.cc
+++ b/services/network/cors/cors_url_loader_factory.cc
@@ -8,7 +8,6 @@
 
 #include "base/bind.h"
 #include "base/logging.h"
-#include "base/metrics/histogram_macros.h"
 #include "mojo/public/cpp/bindings/message.h"
 #include "mojo/public/cpp/bindings/remote.h"
 #include "net/base/load_flags.h"
@@ -477,9 +476,6 @@
   InitiatorLockCompatibility initiator_lock_compatibility =
       VerifyRequestInitiatorLockWithPluginCheck(
           process_id_, request_initiator_origin_lock_, origin_to_validate);
-  UMA_HISTOGRAM_ENUMERATION(
-      "NetworkService.URLLoader.RequestInitiatorOriginLockCompatibility",
-      initiator_lock_compatibility);
   switch (initiator_lock_compatibility) {
     case InitiatorLockCompatibility::kCompatibleLock:
     case InitiatorLockCompatibility::kBrowserProcess:
diff --git a/tools/metrics/histograms/metadata/network/histograms.xml b/tools/metrics/histograms/metadata/network/histograms.xml
index 26a573d..9037cb5 100644
--- a/tools/metrics/histograms/metadata/network/histograms.xml
+++ b/tools/metrics/histograms/metadata/network/histograms.xml
@@ -3170,6 +3170,12 @@
 <histogram
     name="NetworkService.URLLoader.RequestInitiatorOriginLockCompatibility"
     enum="RequestInitiatorOriginLockCompatibility" expires_after="2022-04-10">
+  <obsolete>
+    Removed in March 2022 / M101.
+
+    Old results are preserved in
+    https://docs.google.com/document/d/15j6AKzZ-HgyRQVrKpdGHfGf8D_fcUILmcQ34RAWD1TM/edit?resourcekey=0-wwIJsGSoWmhvFMwMTWdAOw
+  </obsolete>
   <owner>lukasza@chromium.org</owner>
   <owner>creis@chromium.org</owner>
   <owner>jam@chromium.org</owner>