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..d7d1d81e2e10b9ea0b1d59a3398a63f8bd19bf43 100644
--- a/chrome/renderer/plugins/chrome_plugin_placeholder.h
+++ b/chrome/renderer/plugins/chrome_plugin_placeholder.h
@@ -52,6 +52,10 @@ class ChromePluginPlaceholder : public plugins::PluginPlaceholder,
   // WebViewPlugin::Delegate (via PluginPlaceholder) method
   virtual void BindWebFrame(blink::WebFrame* frame) OVERRIDE;
 
+  // gin::Wrappable (via PluginPlaceholder) method
+  virtual gin::ObjectTemplateBuilder GetObjectTemplateBuilder(
+      v8::Isolate* isolate) OVERRIDE;
+
   // content::RenderViewObserver (via PluginPlaceholder) override:
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
@@ -66,9 +70,7 @@ 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);