[Extensions] Clean up the handling of ExtensionHostMsg_Request

extensions/shell/browser/shell_app_delegate.cc

 // Copyright 2014 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/shell/browser/shell_app_delegate.h"
 
 #include "content/public/browser/web_contents.h"
 #include "extensions/common/constants.h"
 #include "extensions/shell/browser/media_capture_util.h"
+#include "extensions/shell/browser/shell_extension_web_contents_observer.h"
 
 namespace extensions {
 
 ShellAppDelegate::ShellAppDelegate() {
 }
 
 ShellAppDelegate::~ShellAppDelegate() {
 }
 
 void ShellAppDelegate::InitWebContents(content::WebContents* web_contents) {
+  ShellExtensionWebContentsObserver::CreateForWebContents(web_contents);
 }
 
 void ShellAppDelegate::RenderViewCreated(
     content::RenderViewHost* render_view_host) {
   // The views implementation of AppWindow takes focus via SetInitialFocus()
   // and views::WebView but app_shell is aura-only and must do it manually.
   content::WebContents::FromRenderViewHost(render_view_host)->Focus();
 }
 
 void ShellAppDelegate::ResizeWebContents(content::WebContents* web_contents,
@@ skipping 63 matching lines @@
     content::WebContents* web_contents) {
   return true;
 }
 
 void ShellAppDelegate::SetTerminatingCallback(const base::Closure& callback) {
   // TODO(jamescook): Should app_shell continue to close the app window
   // manually or should it use a browser termination callback like Chrome?
 }
 
 }  // namespace extensions