Perform navigation policy check on UI thread for --site-per-process.

content/browser/loader/cross_site_resource_handler.h

 // Copyright (c) 2012 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.
 
 #ifndef CONTENT_BROWSER_LOADER_CROSS_SITE_RESOURCE_HANDLER_H_
 #define CONTENT_BROWSER_LOADER_CROSS_SITE_RESOURCE_HANDLER_H_
 
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "content/browser/loader/layered_resource_handler.h"
 #include "content/common/content_export.h"
 #include "net/url_request/url_request_status.h"
 
 namespace net {
 class URLRequest;
 }
 
 namespace content {
 
@@ skipping 33 matching lines @@
   CONTENT_EXPORT static void SetLeakRequestsForTesting(
       bool leak_requests_for_testing);
 
  private:
   // Prepare to render the cross-site response in a new RenderViewHost, by
   // telling the old RenderViewHost to run its onunload handler.
   void StartCrossSiteTransition(int request_id,
                                 ResourceResponse* response,
                                 bool should_transfer);
 
+  // Defer the navigation to the UI thread to check whether transfer is required
+  // or not.

[Charlie Reis, 2014/04/24 23:17:50]

nit: Add "Currently only used in --site-per-process."

[nasko, 2014/04/24 23:29:34]

Done.

+  bool DeferForNavigationPolicyCheck(ResourceRequestInfoImpl* info,
+                                     ResourceResponse* response,
+                                     bool* defer);
+
+  void ResumeOrTransfer(bool is_transfer);
   void ResumeIfDeferred();
 
   // Called when about to defer a request.  Sets |did_defer_| and logs the
   // defferral
   void OnDidDefer();
 
   bool has_started_response_;
   bool in_cross_site_transition_;
   bool completed_during_transition_;
   bool did_defer_;
   net::URLRequestStatus completed_status_;
   std::string completed_security_info_;
   scoped_refptr<ResourceResponse> response_;
 
+  // TODO(nasko): WeakPtr is needed in --site-per-process, since all navigations
+  // are deferred to the UI thread and come back to IO thread via
+  // PostTaskAndReplyWithResult. If a transfer is needed, it goes back to the UI
+  // thread. This can be removed once the code is changed to only do one hop.
+  base::WeakPtrFactory<CrossSiteResourceHandler> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(CrossSiteResourceHandler);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_CROSS_SITE_RESOURCE_HANDLER_H_