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

content/browser/frame_host/navigation_handle_impl_browsertest.cc

 // Copyright 2016 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 "base/memory/weak_ptr.h"
 #include "content/browser/frame_host/navigation_handle_impl.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/common/browser_side_navigation_policy.h"
@@ skipping 1129 matching lines @@
 
 // This class allows running tests with PlzNavigate enabled, regardless of
 // default test configuration.
 class PlzNavigateNavigationHandleImplBrowserTest : public ContentBrowserTest {
  public:
   PlzNavigateNavigationHandleImplBrowserTest() {}
 
   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
 // request from being made are properly committed in the original process
 // 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());
 
   GURL start_url(embedded_test_server()->GetURL("foo.com", "/title1.html"));
   GURL blocked_url(embedded_test_server()->GetURL("bar.com", "/title2.html"));
 
   {
     NavigationHandleObserver observer(shell()->web_contents(), start_url);
     EXPECT_TRUE(NavigateToURL(shell(), start_url));
     EXPECT_TRUE(observer.has_committed());
@@ skipping 15 matching lines @@
     EXPECT_EQ(site_instance,
               shell()->web_contents()->GetMainFrame()->GetSiteInstance());
   }
 }
 
 // Test to verify that error pages caused by network error or other
 // recoverable error are properly committed in the process for the
 // 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());
 
   GURL start_url(embedded_test_server()->GetURL("foo.com", "/title1.html"));
   GURL error_url(
       net::URLRequestFailedJob::GetMockHttpUrl(net::ERR_CONNECTION_RESET));
   EXPECT_NE(start_url.host(), error_url.host());
   BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
                           base::Bind(&net::URLRequestFailedJob::AddUrlHandler));
 
@@ skipping 10 matching lines @@
     NavigationHandleObserver observer(shell()->web_contents(), error_url);
     EXPECT_FALSE(NavigateToURL(shell(), error_url));
     EXPECT_TRUE(observer.has_committed());
     EXPECT_TRUE(observer.is_error());
     EXPECT_NE(site_instance,
               shell()->web_contents()->GetMainFrame()->GetSiteInstance());
   }
 }
 
 }  // namespace content