Refactor PluginService to take PluginList as a dependency.

content/browser/plugin_service.h

Index: content/browser/plugin_service.h
diff --git a/content/browser/plugin_service.h b/content/browser/plugin_service.h
index 2b2c69f225f2812bdcc9a555ecc05acfe6158a6d..9087365bc2315784a4e1a23b558f476a7ae46898 100644
--- a/content/browser/plugin_service.h
+++ b/content/browser/plugin_service.h
@@ -157,11 +157,11 @@ class CONTENT_EXPORT PluginService
 
   // Asynchronously loads plugins if necessary and then calls back to the
   // provided function on the calling MessageLoop on completion.
-  void GetPlugins(const GetPluginsCallback& callback);
+  virtual void GetPlugins(const GetPluginsCallback& callback);
 
   // Asynchronously loads the list of plugin groups if necessary and then calls
   // back to the provided function on the calling MessageLoop on completion.
-  void GetPluginGroups(const GetPluginGroupsCallback& callback);
+  virtual void GetPluginGroups(const GetPluginGroupsCallback& callback);
 
   // Tells all the renderer processes associated with the given browser context
   // to throw away their cache of the plugin list, and optionally also reload
@@ -176,14 +176,18 @@ class CONTENT_EXPORT PluginService
   }
   content::PluginServiceFilter* filter() { return filter_; }
 
- private:
-  friend struct DefaultSingletonTraits<PluginService>;
+  webkit::npapi::PluginList* plugin_list() const { return plugin_list_; }
 
-  // Creates the PluginService object, but doesn't actually build the plugin
-  // list yet.  It's generated lazily.
-  PluginService();
+ protected:
+  // Creates the PluginService object, but the actual plugin list is generated
+  // lazily. If |plugin_list| is NULL, the singleton will be used. In tests,
+  // use MockPluginList for dependency injection.
+  PluginService(webkit::npapi::PluginList* plugin_list = NULL);

[Bernhard Bauer, 2011/11/07 22:37:50]

Could you have a protected mutator to set the plugin list to get around the
default parameter here? We could probably move some of the initialization code
in the constructor that uses |plugin_list| to the client.

[Robert Sesek, 2011/11/07 23:05:49]

No, but I can create a custom singleton traits.

   virtual ~PluginService();
 
+ private:
+  friend struct DefaultSingletonTraits<PluginService>;
+
   // base::WaitableEventWatcher::Delegate implementation.
   virtual void OnWaitableEventSignaled(base::WaitableEvent* waitable_event);
 
@@ -232,6 +236,9 @@ class CONTENT_EXPORT PluginService
       base::files::FilePathWatcher::Delegate* delegate);
 #endif
 
+  // The plugin list instance.
+  webkit::npapi::PluginList* plugin_list_;
+
   // The browser's UI locale.
   const std::string ui_locale_;