Implement transfer navigation with mojo

content/browser/loader/resource_loader.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_RESOURCE_LOADER_H_
 #define CONTENT_BROWSER_LOADER_RESOURCE_LOADER_H_
 
 #include <memory>
 
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
 #include "content/browser/ssl/ssl_client_auth_handler.h"
 #include "content/browser/ssl/ssl_error_handler.h"
 #include "content/common/content_export.h"
+#include "content/common/url_loader.mojom.h"
 #include "content/public/browser/resource_controller.h"
 #include "net/url_request/url_request.h"
 
 namespace net {
 class X509Certificate;
 }
 
 namespace content {
 class ResourceDispatcherHostLoginDelegate;
 class ResourceHandler;
 class ResourceLoaderDelegate;
 class ResourceRequestInfoImpl;
 
 // This class is responsible for driving the URLRequest (i.e., calling Start,
 // Read, and servicing events).  It has a ResourceHandler, which is typically a
 // chain of ResourceHandlers, and is the ResourceController for its handler.
 class CONTENT_EXPORT ResourceLoader : public net::URLRequest::Delegate,
                                       public SSLErrorHandler::Delegate,
                                       public SSLClientAuthHandler::Delegate,
                                       public ResourceController {
+  using TransferCallback =
+      base::Callback<void(mojom::URLLoaderAssociatedRequest,
+                          mojom::URLLoaderClientAssociatedPtr)>;
+
  public:
   ResourceLoader(std::unique_ptr<net::URLRequest> request,
                  std::unique_ptr<ResourceHandler> handler,
                  ResourceLoaderDelegate* delegate);
   ~ResourceLoader() override;
 
   void StartRequest();
   void CancelRequest(bool from_renderer);
 
   bool is_transferring() const { return is_transferring_; }
-  void MarkAsTransferring(const base::Closure& on_transfer_complete_callback);
-  void CompleteTransfer();
+  void MarkAsTransferring(
+      const TransferCallback& on_transfer_complete_callback);
+  void CompleteTransfer(mojom::URLLoaderAssociatedRequest,
+                        mojom::URLLoaderClientAssociatedPtr);
 
   net::URLRequest* request() { return request_.get(); }
   ResourceRequestInfoImpl* GetRequestInfo();
 
   void ClearLoginDelegate();
 
  private:
   // net::URLRequest::Delegate implementation:
   void OnReceivedRedirect(net::URLRequest* request,
                           const net::RedirectInfo& redirect_info,
@@ skipping 64 matching lines @@
   scoped_refptr<ResourceDispatcherHostLoginDelegate> login_delegate_;
   std::unique_ptr<SSLClientAuthHandler> ssl_client_auth_handler_;
 
   base::TimeTicks read_deferral_start_time_;
 
   // Indicates that we are in a state of being transferred to a new downstream
   // consumer.  We are waiting for a notification to complete the transfer, at
   // which point we'll receive a new ResourceHandler.
   bool is_transferring_;
 
   // Called when a navigation has finished transfer.

[clamy, 2016/11/21 17:55:54]

Can you mention that this will update the NavigationThrottle? Now that we have
two TransferCallbacks, the code becomes less clear.

-  base::Closure on_transfer_complete_callback_;
+  TransferCallback on_transfer_complete_callback_;
 
   // Instrumentation add to investigate http://crbug.com/503306.
   // TODO(mmenke): Remove once bug is fixed.
   int times_cancelled_before_request_start_;
   bool started_request_;
   int times_cancelled_after_request_start_;
 
   base::WeakPtrFactory<ResourceLoader> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourceLoader);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_RESOURCE_LOADER_H_