Check media permissions through RenderFrameHostDelegate.

extensions/browser/guest_view/web_view/web_view_permission_helper_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/browser/guest_view/web_view/web_view_permission_helper_delegate.h"
 
 #include "extensions/browser/guest_view/web_view/web_view_guest.h"
 
 namespace extensions {
 
 WebViewPermissionHelperDelegate::WebViewPermissionHelperDelegate(
     WebViewPermissionHelper* web_view_permission_helper)
     : content::WebContentsObserver(
           web_view_permission_helper->web_view_guest()->web_contents()),
       web_view_permission_helper_(web_view_permission_helper) {
 }
 
 WebViewPermissionHelperDelegate::~WebViewPermissionHelperDelegate() {
 }
 
+bool WebViewPermissionHelperDelegate::CheckMediaAccessPermission(
+    content::WebContents* source,
+    const GURL& security_origin,
+    content::MediaStreamType type) {
+  // Defensive default implementation for privacy reasons.
+  return false;
+}
+
 }  // namespace extensions