Avoid sync IPCs for FileSystem API

chrome/renderer/worker_permission_client_proxy.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 "chrome/common/render_messages.h"
 #include "chrome/renderer/worker_permission_client_proxy.h"
 #include "content/public/renderer/render_frame.h"
 #include "content/public/renderer/render_thread.h"
 #include "ipc/ipc_sync_message_filter.h"
+#include "third_party/WebKit/public/platform/WebPermissionCallbacks.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebFrame.h"
 #include "third_party/WebKit/public/web/WebSecurityOrigin.h"
 
 WorkerPermissionClientProxy::WorkerPermissionClientProxy(
     content::RenderFrame* render_frame,
     blink::WebFrame* frame)
     : routing_id_(render_frame->GetRoutingID()),
       is_unique_origin_(false) {
   if (frame->document().securityOrigin().isUnique() ||
@@ skipping 24 matching lines @@
 bool WorkerPermissionClientProxy::allowFileSystem() {
   if (is_unique_origin_)
     return false;
 
   bool result = false;
   sync_message_filter_->Send(new ChromeViewHostMsg_AllowFileSystem(
       routing_id_, document_origin_url_, top_frame_origin_url_, &result));
   return result;
 }
 
+void WorkerPermissionClientProxy::requestFileSystemAccess(
+    const blink::WebPermissionCallbacks& callbacks) {
+  bool result = false;
+  sync_message_filter_->Send(new ChromeViewHostMsg_AllowFileSystem(
+      routing_id_, document_origin_url_, top_frame_origin_url_, &result));
+  blink::WebPermissionCallbacks permission_callbacks(callbacks);
+  if (result) {
+    permission_callbacks.doAllow();
+    return;
+  }
+  permission_callbacks.doDeny();
+}
+
 bool WorkerPermissionClientProxy::allowIndexedDB(
     const blink::WebString& name) {
   if (is_unique_origin_)
     return false;
 
   bool result = false;
   sync_message_filter_->Send(new ChromeViewHostMsg_AllowIndexedDB(
       routing_id_, document_origin_url_, top_frame_origin_url_, name, &result));
   return result;
 }