Add a control group to the SiteIsolationExtensionsActive. It corresponds to the Disabled group of t…

chrome/browser/extensions/chrome_extension_web_contents_observer.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/chrome_extension_web_contents_observer.h"
 
 #include "base/command_line.h"
+#include "base/metrics/field_trial.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/error_console/error_console.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/window_controller.h"
 #include "chrome/browser/metrics/chrome_metrics_service_accessor.h"
 #include "chrome/common/extensions/chrome_extension_messages.h"
 #include "chrome/common/extensions/extension_process_policy.h"
 #include "chrome/common/url_constants.h"
 #include "components/rappor/rappor_service.h"
 #include "content/public/browser/browser_context.h"
@@ skipping 180 matching lines @@
     } else if (extensions::IsIsolateExtensionsEnabled()) {
       if (base::CommandLine::ForCurrentProcess()->HasSwitch(
               switches::kIsolateExtensions)) {
         ChromeMetricsServiceAccessor::RegisterSyntheticFieldTrial(
             "SiteIsolationExtensionsActive", "IsolateExtensionsFlag");
       } else {
         ChromeMetricsServiceAccessor::RegisterSyntheticFieldTrial(
             "SiteIsolationExtensionsActive", "FieldTrial");
       }
     } else {
-      ChromeMetricsServiceAccessor::RegisterSyntheticFieldTrial(
-          "SiteIsolationExtensionsActive", "Default");
+      if (!base::FieldTrialList::FindFullName("SiteIsolationExtensions")
+               .empty()) {
+        // The field trial is active, but we are in a control group with oopifs
+        // disabled.
+        ChromeMetricsServiceAccessor::RegisterSyntheticFieldTrial(
+            "SiteIsolationExtensionsActive", "Control");
+      } else {
+        // The field trial is not active for this version.
+        ChromeMetricsServiceAccessor::RegisterSyntheticFieldTrial(
+            "SiteIsolationExtensionsActive", "Default");
+      }
     }
 
     if (rappor::RapporService* rappor = g_browser_process->rappor_service()) {
       const std::string& extension_id =
           parent_is_extension ? parent_url.host() : frame_url.host();
       rappor->RecordSample("Extensions.AffectedByIsolateExtensions",
                            rappor::UMA_RAPPOR_TYPE, extension_id);
     }
   }
 }
 
 }  // namespace extensions