Adding --disable-plugins-discovery command line switch to not load third-party plugins from common …

chrome/browser/browser_process_impl.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 "chrome/browser/browser_process_impl.h"
 
 #include <algorithm>
 #include <map>
 #include <vector>
 
@@ skipping 855 matching lines @@
     ApplyDefaultBrowserPolicy();
 
 #if defined(ENABLE_PLUGINS)
   PluginService* plugin_service = PluginService::GetInstance();
   plugin_service->SetFilter(ChromePluginServiceFilter::GetInstance());
   plugin_service->StartWatchingPlugins();
 
 #if defined(OS_POSIX)
   // Also find plugins in a user-specific plugins dir,
   // e.g. ~/.config/chromium/Plugins.
-  base::FilePath user_data_dir;
-  if (PathService::Get(chrome::DIR_USER_DATA, &user_data_dir))
-    plugin_service->AddExtraPluginDir(user_data_dir.Append("Plugins"));
+  const CommandLine& cmd_line = *CommandLine::ForCurrentProcess();
+  if (!cmd_line.HasSwitch(switches::kDisablePluginsDiscovery)) {
+    base::FilePath user_data_dir;
+    if (PathService::Get(chrome::DIR_USER_DATA, &user_data_dir))
+      plugin_service->AddExtraPluginDir(user_data_dir.Append("Plugins"));
+  }
 #endif
 
   // Triggers initialization of the singleton instance on UI thread.
   PluginFinder::GetInstance()->Init();
 
 #if defined(ENABLE_PLUGIN_INSTALLATION)
   DCHECK(!plugins_resource_service_.get());
   plugins_resource_service_ = new PluginsResourceService(local_state());
   plugins_resource_service_->Init();
 #endif
@@ skipping 145 matching lines @@
 }
 
 void BrowserProcessImpl::OnAutoupdateTimer() {
   if (CanAutorestartForUpdate()) {
     DLOG(WARNING) << "Detected update.  Restarting browser.";
     RestartBackgroundInstance();
   }
 }
 
 #endif  // (defined(OS_WIN) || defined(OS_LINUX)) && !defined(OS_CHROMEOS)