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

chrome/browser/browser_process_impl.cc

Index: chrome/browser/browser_process_impl.cc
===================================================================
--- chrome/browser/browser_process_impl.cc	(revision 204062)
+++ chrome/browser/browser_process_impl.cc	(working copy)
@@ -167,7 +167,8 @@
       using_new_frames_(false),
       render_widget_snapshot_taker_(new RenderWidgetSnapshotTaker),
       download_status_updater_(new DownloadStatusUpdater),
-      local_state_task_runner_(local_state_task_runner) {
+      local_state_task_runner_(local_state_task_runner),
+      command_line_(command_line) {
   g_browser_process = this;
   platform_part_.reset(new BrowserProcessPlatformPart());
 
@@ -884,9 +885,11 @@
 #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"));
+  if (!command_line_.HasSwitch(switches::kDisablePluginsDiscovery)) {

[seva, 2013/06/06 22:11:25]

On this note, it feels that this "Plugins" directory should be a part of what
PluginList::GetPluginDirectories() returns.

That way these "if
(!command_line_.HasSwitch(switches::kDisablePluginsDiscovery))" checks are
better localized.

Also, functionally, this directory is being "watched" for file changes and
related functionality works too (See PluginServiceImpl::StartWatchingPlugins(),
https://code.google.com/p/chromium/codesearch#chromium/src/content/browser/pl...
).

If what I'm saying makes sense and fixing this isn't too involved I'm happy to
work on addressing; separately from BUG=239325

[Bernhard Bauer, 2013/06/07 10:33:43]

Well, this directory is not being returned by default by PluginList because it's
meant to contain plug-ins that are specific to Chrome. 

PluginList is part of the general framework for a multi-process browser
("content"), which shouldn't contain Chrome-specific code. The other plug-in
locations are used by other browsers (Firefox and Safari on Mac, specifically).

That being said, ...
...hmm, it would indeed make sense for PluginList::GetPluginDirectories() to
return extra plug-in directories as well. That would make watching for changes
work automatically, and we'd need to check the switch only once.

+    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.
@@ -899,8 +902,7 @@
 #endif
 #endif  // defined(ENABLE_PLUGINS)
 
-  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
-  if (!command_line.HasSwitch(switches::kDisableWebResources)) {
+  if (!command_line_.HasSwitch(switches::kDisableWebResources)) {
     DCHECK(!promo_resource_service_.get());
     promo_resource_service_ = new PromoResourceService;
     promo_resource_service_->StartAfterDelay();