Disable renderer backgrounding in Chrome Navigation Browser Test

chrome/browser/chrome_navigation_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/command_line.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/renderer_context_menu/render_view_context_menu_test_util.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "chrome/test/base/ui_test_utils.h"
 #include "components/url_formatter/url_formatter.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents_observer.h"
+#include "content/public/common/content_switches.h"
 #include "content/public/common/context_menu_params.h"
 #include "content/public/common/url_constants.h"
 #include "content/public/test/browser_test_utils.h"
 #include "content/public/test/test_navigation_observer.h"
 #include "net/dns/mock_host_resolver.h"
 
 class ChromeNavigationBrowserTest : public InProcessBrowserTest {
  public:
   ChromeNavigationBrowserTest() {}
   ~ChromeNavigationBrowserTest() override {}
 
   void SetUpCommandLine(base::CommandLine* command_line) override {
+    // Backgrounded renderer processes run at a lower priority, causing the
+    // tests to take more time to complete. Disable backgrounding so that the
+    // tests don't time out.
+    command_line->AppendSwitch(switches::kDisableRendererBackgrounding);
+
     ASSERT_TRUE(embedded_test_server()->Start());
   }
 
   void StartServerWithExpiredCert() {
     expired_https_server_.reset(
         new net::EmbeddedTestServer(net::EmbeddedTestServer::TYPE_HTTPS));
     expired_https_server_->SetSSLConfig(net::EmbeddedTestServer::CERT_EXPIRED);
     expired_https_server_->AddDefaultHandlers(
         base::FilePath(FILE_PATH_LITERAL("chrome/test/data")));
     ASSERT_TRUE(expired_https_server_->Start());
@@ skipping 202 matching lines @@
       browser()->tab_strip_model()->GetWebContentsAt(
           browser()->tab_strip_model()->count() - 1);
   WaitForLoadStop(new_web_contents);
 
   // If the test is unsuccessful, the return value from GetLastCommittedURL
   // will be the virtual URL for the created NavigationEntry.
   // Note: Before the bug was fixed, the URL was the new_tab_url with a scheme
   // prepended and one less ":" character after the host.
   EXPECT_EQ(GURL(), new_web_contents->GetLastCommittedURL());
 }