Adds support for media permission request handling on <appview> tag.

chrome/browser/guest_view/app_view/chrome_app_view_guest_delegate.cc

Index: chrome/browser/guest_view/app_view/chrome_app_view_guest_delegate.cc
diff --git a/chrome/browser/guest_view/app_view/chrome_app_view_guest_delegate.cc b/chrome/browser/guest_view/app_view/chrome_app_view_guest_delegate.cc
index f8000df8519a83d0767b5ffa58348326fa220625..071d448fad821c079b4eca487038103fbb3086e7 100644
--- a/chrome/browser/guest_view/app_view/chrome_app_view_guest_delegate.cc
+++ b/chrome/browser/guest_view/app_view/chrome_app_view_guest_delegate.cc
@@ -2,8 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "chrome/browser/apps/scoped_keep_alive.h"
 #include "chrome/browser/guest_view/app_view/chrome_app_view_guest_delegate.h"
 #include "chrome/browser/renderer_context_menu/render_view_context_menu.h"
+#include "chrome/browser/ui/apps/chrome_app_delegate.h"
 #include "components/renderer_context_menu/context_menu_delegate.h"
 
 namespace extensions {
@@ -27,4 +29,8 @@ bool ChromeAppViewGuestDelegate::HandleContextMenu(
   return true;
 }
 
+AppDelegate* ChromeAppViewGuestDelegate::CreateAppDelegate() {
+  return new ChromeAppDelegate(make_scoped_ptr(new ScopedKeepAlive));
+}
+
 }  // namespace extensions