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 0e8bcb9cfb6adfdf28a61ca33772a2432021c62c..bc173beb8d8820fe2e784f433e6583bfd08a6fae 100644
--- a/content/browser/plugin_service.h
+++ b/content/browser/plugin_service.h
@@ -81,6 +81,9 @@ class CONTENT_EXPORT PluginService
   // Returns the PluginService singleton.
   static PluginService* GetInstance();
 
+  // Must be called on the instance to finish initialization.
+  void Init();
+
   // Starts watching for changes in the list of installed plug-ins.
   void StartWatchingPlugins();
 
@@ -173,7 +176,6 @@ class CONTENT_EXPORT PluginService
   }
   content::PluginServiceFilter* filter() { return filter_; }
 
-
   // The following functions are wrappers around webkit::npapi::PluginList.
   // These must be used instead of those in order to ensure that we have a
   // single global list in the component build and so that we don't
@@ -189,6 +191,8 @@ class CONTENT_EXPORT PluginService
   // TODO(dpranke): This should be private.
   webkit::npapi::PluginList* plugin_list();
 
+  void SetPluginListForTesting(webkit::npapi::PluginList* plugin_list);
+
  private:
   friend struct DefaultSingletonTraits<PluginService>;
 
@@ -245,6 +249,12 @@ class CONTENT_EXPORT PluginService
       base::files::FilePathWatcher::Delegate* delegate);
 #endif
 
+  // Whether or not the Init() method was called.
+  bool did_init_;
+
+  // The plugin list instance.
+  webkit::npapi::PluginList* plugin_list_;
+
   // The browser's UI locale.
   const std::string ui_locale_;