Block NPAPI plugins by default

chrome/browser/prerender/prerender_browsertest.cc

 // Copyright (c) 2012 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 <deque>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
@@ skipping 1064 matching lines @@
 #if defined(OS_MACOSX)
     // The plugins directory isn't read by default on the Mac, so it needs to be
     // explicitly registered.
     base::FilePath app_dir;
     PathService::Get(chrome::DIR_APP, &app_dir);
     command_line->AppendSwitchPath(
         switches::kExtraPluginDir,
         app_dir.Append(FILE_PATH_LITERAL("plugins")));
 #endif
     command_line->AppendSwitch(switches::kAlwaysAuthorizePlugins);
+    command_line->AppendSwitch(switches::kEnableNpapi);
   }
 
   void SetPreference(NetworkPredictionOptions value) {
     browser()->profile()->GetPrefs()->SetInteger(
         prefs::kNetworkPredictionOptions, value);
   }
 
   void CreateTestFieldTrial(const std::string& name,
                             const std::string& group_name) {
     base::FieldTrial* trial = base::FieldTrialList::CreateFieldTrial(
@@ skipping 3227 matching lines @@
   TestShouldDisableLocalPredictorPreferenceNetworkMatrix(
       true /*preference_wifi_network_wifi*/,
       true /*preference_wifi_network_4g*/,
       true /*preference_always_network_wifi*/,
       false /*preference_always_network_4g*/,
       true /*preference_never_network_wifi*/,
       true /*preference_never_network_4g*/);
 }
 
 }  // namespace prerender