Avoid changing enabled features while the browser is already running.

content/browser/frame_host/data_url_navigation_browsertest.cc

 // Copyright 2017 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 "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/macros.h"
 #include "base/path_service.h"
 #include "base/strings/pattern.h"
@@ skipping 489 matching lines @@
 // Tests that a content initiated navigation to a data URL is blocked.
 IN_PROC_BROWSER_TEST_F(DataUrlNavigationBrowserTest, HTML_Navigation_Block) {
   NavigateToURL(shell(),
                 embedded_test_server()->GetURL("/data_url_navigations.html"));
   ExecuteScriptAndCheckNavigation(
       shell()->web_contents()->GetMainFrame(),
       "document.getElementById('navigate-top-frame-to-html').click()",
       NAVIGATION_BLOCKED);
 }
 
+class DataUrlNavigationAllowedFromContentTest
+    : public DataUrlNavigationBrowserTest {
+ public:
+  DataUrlNavigationAllowedFromContentTest() {}
+
+ protected:
+  void SetUp() override {
+    scoped_feature_list_.InitAndEnableFeature(
+        features::kAllowContentInitiatedDataUrlNavigations);
+    DataUrlNavigationBrowserTest::SetUp();
+  }
+
+ private:
+  base::test::ScopedFeatureList scoped_feature_list_;
+
+  DISALLOW_COPY_AND_ASSIGN(DataUrlNavigationAllowedFromContentTest);
+};
+
 // Tests that a content initiated navigation to a data URL is allowed if
 // blocking is disabled with a feature flag.
-IN_PROC_BROWSER_TEST_F(DataUrlNavigationBrowserTest,
-                       HTML_Navigation_Allow_FeatureFlag) {
-  base::test::ScopedFeatureList feature_list;
-  feature_list.InitAndEnableFeature(
-      features::kAllowContentInitiatedDataUrlNavigations);
+IN_PROC_BROWSER_TEST_F(DataUrlNavigationAllowedFromContentTest,
+                       HTML_Navigation) {
   NavigateToURL(shell(),
                 embedded_test_server()->GetURL("/data_url_navigations.html"));
   ExecuteScriptAndCheckNavigation(
       shell()->web_contents()->GetMainFrame(),
       "document.getElementById('navigate-top-frame-to-html').click()",
       NAVIGATION_ALLOWED);
 }
 
 // Tests that a window.open to a data URL with HTML mime type is blocked.
 IN_PROC_BROWSER_TEST_F(DataUrlNavigationBrowserTest, HTML_WindowOpen_Block) {
@@ skipping 406 matching lines @@
   ASSERT_TRUE(child);
   if (AreAllSitesIsolatedForTesting()) {
     ASSERT_TRUE(child->IsCrossProcessSubframe());
   }
   ExecuteScriptAndCheckNavigationDownload(
       child, "document.getElementById('window-open-pdf').click()");
 #endif
 }
 
 }  // content