Ensure all content_browsertests call the host resolver in SetUpOnMainThread and not after.

content/browser/frame_host/navigation_handle_impl_browsertest.cc

Index: content/browser/frame_host/navigation_handle_impl_browsertest.cc
diff --git a/content/browser/frame_host/navigation_handle_impl_browsertest.cc b/content/browser/frame_host/navigation_handle_impl_browsertest.cc
index 64a6b3bfc22750b1e1fe9ee6cb43ee766e838627..892d64c073d6de341f216bc194deb716b3b60e3b 100644
--- a/content/browser/frame_host/navigation_handle_impl_browsertest.cc
+++ b/content/browser/frame_host/navigation_handle_impl_browsertest.cc
@@ -1147,6 +1147,10 @@ class PlzNavigateNavigationHandleImplBrowserTest : public ContentBrowserTest {
   void SetUpCommandLine(base::CommandLine* command_line) override {
     command_line->AppendSwitch(switches::kEnableBrowserSideNavigation);
   }
+
+  void SetUpOnMainThread() override {
+    host_resolver()->AddRule("*", "127.0.0.1");
+  }
 };
 
 // Test to verify that error pages caused by NavigationThrottle blocking a
@@ -1154,7 +1158,6 @@ class PlzNavigateNavigationHandleImplBrowserTest : public ContentBrowserTest {
 // that requested the navigation.
 IN_PROC_BROWSER_TEST_F(PlzNavigateNavigationHandleImplBrowserTest,
                        ErrorPageBlockedNavigation) {
-  host_resolver()->AddRule("*", "127.0.0.1");
   SetupCrossSiteRedirector(embedded_test_server());
   ASSERT_TRUE(embedded_test_server()->Start());
 
@@ -1190,7 +1193,6 @@ IN_PROC_BROWSER_TEST_F(PlzNavigateNavigationHandleImplBrowserTest,
 // destination URL.
 IN_PROC_BROWSER_TEST_F(PlzNavigateNavigationHandleImplBrowserTest,
                        ErrorPageNetworkError) {
-  host_resolver()->AddRule("*", "127.0.0.1");
   SetupCrossSiteRedirector(embedded_test_server());
   ASSERT_TRUE(embedded_test_server()->Start());