[Extensions] Clean up the handling of ExtensionHostMsg_Request

extensions/browser/extension_function.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "extensions/browser/extension_function.h"
 
 #include "base/logging.h"
 #include "base/memory/singleton.h"
 #include "base/synchronization/lock.h"
 #include "content/public/browser/notification_source.h"
@@ skipping 446 matching lines @@
 void UIThreadExtensionFunction::SetRenderFrameHost(
     content::RenderFrameHost* render_frame_host) {
   DCHECK(!render_view_host_);
   render_frame_host_ = render_frame_host;
   tracker_.reset(render_frame_host ? new RenderHostTracker(this) : NULL);
 }
 
 content::WebContents* UIThreadExtensionFunction::GetAssociatedWebContents() {
   content::WebContents* web_contents = NULL;
   if (dispatcher())
-    web_contents = dispatcher()->delegate()->GetAssociatedWebContents();
+    web_contents = dispatcher()->GetAssociatedWebContents();
 
   return web_contents;
 }
 
 content::WebContents* UIThreadExtensionFunction::GetSenderWebContents() {
   return render_view_host_ ?
       content::WebContents::FromRenderViewHost(render_view_host_) : nullptr;
 }
 
 void UIThreadExtensionFunction::SendResponse(bool success) {
@@ skipping 103 matching lines @@
 
 ExtensionFunction::ResponseAction SyncIOThreadExtensionFunction::Run() {
   return RespondNow(RunSync() ? ArgumentList(results_.Pass()) : Error(error_));
 }
 
 // static
 bool SyncIOThreadExtensionFunction::ValidationFailure(
     SyncIOThreadExtensionFunction* function) {
   return false;
 }