PlzNavigate: fix expectation in NavigationControllerBrowserTest

This fixes one expectation in
NavigationControllerBrowserTest.FrameNavigationEntry_FrameUniqueName following
PlzNavigate switch to frame history entries.

BUG=575210

Review URL: https://codereview.chromium.org/1631273003

Cr-Commit-Position: refs/heads/master@{#372104}

content/browser/frame_host/navigation_controller_impl_browsertest.cc

@@ -2605,8 +2605,18 @@ IN_PROC_BROWSER_TEST_F(NavigationControllerBrowserTest,
       "bar.com", "/navigation_controller/simple_page_1.html"));
   NavigateFrameToURL(foo_subframe, bar_url);
   EXPECT_TRUE(WaitForLoadStop(shell()->web_contents()));
-  EXPECT_NE(main_site_instance,
-            foo_subframe->current_frame_host()->GetSiteInstance());
+
+  // When run just with subframe navigation entries enabled and not in
+  // site-per-process-mode the subframe should be in the same SiteInstance as
+  // its parent.
+  if (!SiteIsolationPolicy::AreCrossProcessFramesPossible()) {
+    EXPECT_EQ(main_site_instance,
+              foo_subframe->current_frame_host()->GetSiteInstance());
+  } else {
+    EXPECT_NE(main_site_instance,
+              foo_subframe->current_frame_host()->GetSiteInstance());
+  }
+
   foo_subframe_entry =
       controller.GetLastCommittedEntry()->GetFrameEntry(foo_subframe);
   EXPECT_EQ(named_subframe_name, foo_subframe_entry->frame_unique_name());

testing/buildbot/filters/browser-side-navigation.linux.content_browsertests.filter

@@ -16,7 +16,6 @@
 -LoFiResourceDispatcherHostBrowserTest.ShouldEnableLoFiModeReload
 -LoFiResourceDispatcherHostBrowserTest.ShouldEnableLoFiModeReloadDisableLoFi
 -NavigationControllerBrowserTest.CorrectLengthWithCurrentItemReplacement
--NavigationControllerBrowserTest.FrameNavigationEntry_FrameUniqueName
 -NavigationControllerBrowserTest.FrameNavigationEntry_SubframeHistoryFallback
 -NavigationControllerBrowserTest.NavigationTypeClassification_ClientSideRedirect
 -NavigationControllerBrowserTest.NavigationTypeClassification_EmptyGURL