Move the plugin placeholder from CppBoundClass to gin::Wrappable

chrome/renderer/plugins/chrome_plugin_placeholder.h

Index: chrome/renderer/plugins/chrome_plugin_placeholder.h
diff --git a/chrome/renderer/plugins/chrome_plugin_placeholder.h b/chrome/renderer/plugins/chrome_plugin_placeholder.h
index 66869207a28f81c431a7ffb40d04b4af6a1ec222..25465f81af5e36413ac9c927243c4b656a8a05b4 100644
--- a/chrome/renderer/plugins/chrome_plugin_placeholder.h
+++ b/chrome/renderer/plugins/chrome_plugin_placeholder.h
@@ -49,6 +49,9 @@ class ChromePluginPlaceholder : public plugins::PluginPlaceholder,
                           const base::string16& title);
   virtual ~ChromePluginPlaceholder();
 
+  // gin::WrappableBase (via plugins::PluginPlaceholder)
+  virtual gin::ObjectTemplateBuilder GetObjectTemplateBuilder(v8::Isolate* isolate) OVERRIDE;
+
   // WebViewPlugin::Delegate (via PluginPlaceholder) method
   virtual void BindWebFrame(blink::WebFrame* frame) OVERRIDE;
 
@@ -66,9 +69,7 @@ class ChromePluginPlaceholder : public plugins::PluginPlaceholder,
   virtual void OnMenuClosed(int request_id) OVERRIDE;
 
   // Javascript callback opens chrome://plugins in a new tab.
-  // Arguments are required by the caller, but not used.
-  void OpenAboutPluginsCallback(const webkit_glue::CppArgumentList& args,
-                                webkit_glue::CppVariant* result);
+  void OpenAboutPluginsCallback();
 
   void OnLoadBlockedPlugins(const std::string& identifier);
   void OnSetIsPrerendering(bool is_prerendering);