Only permit plug-in loads in the browser if the plug-in isn't blocked or the

content/public/browser/plugin_service_filter.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_PLUGIN_SERVICE_FILTER_H_
 #define CONTENT_PUBLIC_BROWSER_PLUGIN_SERVICE_FILTER_H_
 
 class GURL;
 
 namespace webkit {
 struct WebPluginInfo;
 }
 
 namespace content {
 
-// Callback class to let the client filter the list of all installed plug-ins.
+// Callback class to let the client filter the list of all installed plug-ins
+// and block them from being loaded.
 // This class is called on the FILE thread.
 class PluginServiceFilter {
  public:
   virtual ~PluginServiceFilter() {}
 
-  // Whether to use |plugin|. The client can return false to disallow the
+  // Whether |plugin| is enabled. The client can return false to hide the
   // plugin, or return true and optionally change the passed in plugin.
-  virtual bool ShouldUsePlugin(int render_process_id,
+  virtual bool IsPluginEnabled(int render_process_id,

[Bernhard Bauer, 2013/02/04 13:58:53]

Naming bikeshedding comment: I think this confuses the terminology a bit. A
plug-in being "enabled" or "disabled" so far has referred to the user
consciously tweaking things in chrome://plugins, whereas the content interface
is a bit more general (for one, content doesn't know about user preferences that
enable/disable things, and furthermore, there might be other reasons why a
plug-in is not available, like extension-private plug-ins.) Would it be horrible
to change this to "available" or something?

                                int render_view_id,
                                const void* context,
                                const GURL& url,
                                const GURL& policy_url,
                                webkit::WebPluginInfo* plugin) = 0;
+
+  // Whether the renderer has permission to load enabled |plugin|.
+  virtual bool CanLoadPlugin(int render_process_id,
+                             const FilePath& path) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_PLUGIN_SERVICE_FILTER_H_