[Extensions] Clean up the handling of ExtensionHostMsg_Request

extensions/browser/guest_view/extension_view/extension_view_guest.cc

Index: extensions/browser/guest_view/extension_view/extension_view_guest.cc
diff --git a/extensions/browser/guest_view/extension_view/extension_view_guest.cc b/extensions/browser/guest_view/extension_view/extension_view_guest.cc
index b9f73f49dc33ed697424b4f3f0e0df469d3fa81f..ff2bcf98794b1d47d6e7968fe9a72a0ca09c024c 100644
--- a/extensions/browser/guest_view/extension_view/extension_view_guest.cc
+++ b/extensions/browser/guest_view/extension_view/extension_view_guest.cc
@@ -28,10 +28,7 @@ const char ExtensionViewGuest::Type[] = "extensionview";
 
 ExtensionViewGuest::ExtensionViewGuest(
     content::WebContents* owner_web_contents)
-    : GuestView<ExtensionViewGuest>(owner_web_contents),
-      extension_view_guest_delegate_(
-          extensions::ExtensionsAPIClient::Get()
-              ->CreateExtensionViewGuestDelegate(this)) {
+    : GuestView<ExtensionViewGuest>(owner_web_contents) {
 }
 
 ExtensionViewGuest::~ExtensionViewGuest() {
@@ -104,11 +101,7 @@ void ExtensionViewGuest::CreateWebContents(
 
 void ExtensionViewGuest::DidInitialize(
     const base::DictionaryValue& create_params) {
-  extension_function_dispatcher_.reset(
-      new extensions::ExtensionFunctionDispatcher(browser_context(), this));
-
-  if (extension_view_guest_delegate_)
-    extension_view_guest_delegate_->DidInitialize();
+  ExtensionsAPIClient::Get()->AttachWebContentsHelpers(web_contents());
 
   ApplyAttributes(create_params);
 }
@@ -157,22 +150,6 @@ void ExtensionViewGuest::DidNavigateMainFrame(
   }
 }
 
-bool ExtensionViewGuest::OnMessageReceived(const IPC::Message& message) {
-  bool handled = true;
-  IPC_BEGIN_MESSAGE_MAP(ExtensionViewGuest, message)
-  IPC_MESSAGE_HANDLER(ExtensionHostMsg_Request, OnRequest)
-  IPC_MESSAGE_UNHANDLED(handled = false)
-  IPC_END_MESSAGE_MAP()
-  return handled;
-}
-
-// Private
-void ExtensionViewGuest::OnRequest(
-    const ExtensionHostMsg_Request_Params& params) {
-  extension_function_dispatcher_->Dispatch(params,
-                                           web_contents()->GetRenderViewHost());
-}
-
 void ExtensionViewGuest::ApplyAttributes(const base::DictionaryValue& params) {
   std::string src;
   params.GetString(extensionview::kAttributeSrc, &src);