Bind plugin placeholder directly to v8 instead of over CppBoundClass

chrome/renderer/plugins/chrome_plugin_placeholder.cc

Index: chrome/renderer/plugins/chrome_plugin_placeholder.cc
diff --git a/chrome/renderer/plugins/chrome_plugin_placeholder.cc b/chrome/renderer/plugins/chrome_plugin_placeholder.cc
index 7b7506dcdbaf2404a30b8ca5ff4d629b87d39e91..0aba7d85ad9c4aa83cc6d3b19d91b0ec3755dc57 100644
--- a/chrome/renderer/plugins/chrome_plugin_placeholder.cc
+++ b/chrome/renderer/plugins/chrome_plugin_placeholder.cc
@@ -35,8 +35,6 @@ using blink::WebNode;
 using blink::WebPlugin;
 using blink::WebPluginContainer;
 using blink::WebPluginParams;
-using webkit_glue::CppArgumentList;
-using webkit_glue::CppVariant;
 
 namespace {
 const plugins::PluginPlaceholder* g_last_active_menu = NULL;
@@ -64,6 +62,7 @@ ChromePluginPlaceholder::ChromePluginPlaceholder(
       has_host_(false),
       context_menu_request_id_(0) {
   RenderThread::Get()->AddObserver(this);
+  RegisterCallback("openAboutPlugins");
 }
 
 ChromePluginPlaceholder::~ChromePluginPlaceholder() {
@@ -217,13 +216,6 @@ void ChromePluginPlaceholder::OnLoadBlockedPlugins(
   plugins::PluginPlaceholder::OnLoadBlockedPlugins(identifier);
 }
 
-void ChromePluginPlaceholder::OpenAboutPluginsCallback(
-    const CppArgumentList& args,
-    CppVariant* result) {
-  RenderThread::Get()->Send(
-      new ChromeViewHostMsg_OpenAboutPlugins(routing_id()));
-}
-
 void ChromePluginPlaceholder::OnSetIsPrerendering(bool is_prerendering) {
   plugins::PluginPlaceholder::OnSetIsPrerendering(is_prerendering);
 }
@@ -352,9 +344,8 @@ void ChromePluginPlaceholder::ShowContextMenu(const WebMouseEvent& event) {
   g_last_active_menu = this;
 }
 
-void ChromePluginPlaceholder::BindWebFrame(blink::WebFrame* frame) {
-  plugins::PluginPlaceholder::BindWebFrame(frame);
-  BindCallback("openAboutPlugins",
-               base::Bind(&ChromePluginPlaceholder::OpenAboutPluginsCallback,
-                          base::Unretained(this)));
+void ChromePluginPlaceholder::Observe(const std::string& callback) {
+  DCHECK_EQ("openAboutPlugins", callback);
+  RenderThread::Get()->Send(
+      new ChromeViewHostMsg_OpenAboutPlugins(routing_id()));
 }