Adjust test expectations - site-per-process is no longer differs on official bots

r584254 removed differences between waterfall/cq and official bots
(by removing testing/variations/fieldtrial_testing_config.json entries
related to site-per-process and making site-per-process the default
even in absence of field trials).  This makes it possible to remove
the |#if defined(OFFICIAL_BUILD)|-related expectations from
WebDriverSitePerProcessPolicyBrowserTest.

r581059 removed the not_site_per_process_browser_tests step from the bots.
This makes it possible to remove the kDisableSiteIsolationTrials-related
expectations from WebDriverSitePerProcessPolicyBrowserTest

Bug: 874998
Tbr: pastarmovj@chromium.org
Change-Id: I87988884dfe945f16e10680637b26fb4efcf3f2c
Reviewed-on: https://chromium-review.googlesource.com/1181526
Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
Reviewed-by: Nasko Oskov <nasko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584494}

chrome/browser/policy/site_isolation_policy_browsertest.cc

@@ -116,31 +116,9 @@ class IsolateOriginsPolicyBrowserTest : public SiteIsolationPolicyBrowserTest {
 class WebDriverSitePerProcessPolicyBrowserTest
     : public SitePerProcessPolicyBrowserTestEnabled {
  protected:
-  WebDriverSitePerProcessPolicyBrowserTest()
-      : are_sites_isolated_for_testing_(false) {}
+  WebDriverSitePerProcessPolicyBrowserTest() = default;
 
   void SetUpInProcessBrowserTestFixture() override {
-    // First take note if tests are running in site isolated environment as this
-    // will change the outcome of the test. We can't just call this method after
-    // the call to the base setup method because setting the Site Isolation
-    // policy is indistinguishable from setting the the command line flag
-    // directly.
-#if defined(OFFICIAL_BUILD)
-    // Official builds still default to no site isolation (i.e. official builds
-    // are not covered by testing/variations/fieldtrial_testing_config.json).
-    // See also https://crbug.com/836261.
-    are_sites_isolated_for_testing_ = false;
-#else
-    // Otherwise, site-per-process is turned on by default, via field trial
-    // configured with testing/variations/fieldtrial_testing_config.json.
-    // The only exception is the not_site_per_process_browser_tests step run on
-    // some trybots - in this step the --disable-site-isolation-trials flag
-    // counteracts the effects of fieldtrial_testing_config.json.
-    are_sites_isolated_for_testing_ =
-        !base::CommandLine::ForCurrentProcess()->HasSwitch(
-            switches::kDisableSiteIsolationTrials);
-#endif
-
     // We setup the policy here, because the policy must be 'live' before the
     // renderer is created, since the value for this policy is passed to the
     // renderer via a command-line. Setting the policy in the test itself or in
@@ -156,8 +134,6 @@ class WebDriverSitePerProcessPolicyBrowserTest
     provider_.UpdateChromePolicy(values);
   }
 
-  bool are_sites_isolated_for_testing_;
-
  private:
   DISALLOW_COPY_AND_ASSIGN(WebDriverSitePerProcessPolicyBrowserTest);
 };
@@ -200,8 +176,8 @@ IN_PROC_BROWSER_TEST_F(IsolateOriginsPolicyBrowserTest, Simple) {
 
 IN_PROC_BROWSER_TEST_F(WebDriverSitePerProcessPolicyBrowserTest, Simple) {
   Expectations expectations[] = {
-      {"https://foo.com/noodles.html", are_sites_isolated_for_testing_},
-      {"http://example.org/pumpkins.html", are_sites_isolated_for_testing_},
+      {"https://foo.com/noodles.html", true},
+      {"http://example.org/pumpkins.html", true},
   };
   CheckExpectations(expectations, arraysize(expectations));
 }