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

chrome/browser/site_details_browsertest.cc

 // Copyright 2015 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/site_details.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <utility>
@@ skipping 1079 matching lines @@
           switches::kSitePerProcess)) {
     group = "SitePerProcessFlag";
   } else if (extensions::IsIsolateExtensionsEnabled()) {
     if (base::CommandLine::ForCurrentProcess()->HasSwitch(
             extensions::switches::kIsolateExtensions)) {
       group = "IsolateExtensionsFlag";
     } else {
       group = "FieldTrial";
     }
   } else {
-    group = "Default";
+    if (base::FieldTrialList::FindFullName("SiteIsolationExtensions").empty())
+      group = "Default";
+    else
+      group = "Control";
   }
 
   EXPECT_TRUE(IsInTrialGroup("SiteIsolationExtensionsActive", group));
 }
 
 // Verifies that the UMA counter for SiteInstances in a BrowsingInstance is
 // correct when using tabs with web pages.
 IN_PROC_BROWSER_TEST_F(SiteDetailsBrowserTest,
                        VerifySiteInstanceCountInBrowsingInstance) {
   // Page with 14 nested oopifs across 9 sites (a.com through i.com).
@@ skipping 114 matching lines @@
   content::NavigateIframeToURL(
       tab, "child-1", extension2->GetResourceURL("/blank_iframe.html"));
   details = new TestMemoryDetails();
   details->StartFetchAndWait();
   EXPECT_THAT(details->uma()->GetAllSamples(
                   "SiteIsolation.SiteInstancesPerBrowsingInstance"),
               DependingOnPolicy(ElementsAre(Bucket(1, 2)),
                                 ElementsAre(Bucket(1, 1), Bucket(3, 1)),
                                 ElementsAre(Bucket(1, 1), Bucket(5, 1))));
 }