PlzNavigate: make NavigationResourceHandler a LayeredResourceHandler

content/browser/loader/navigation_resource_handler.h

 // 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.
 
 #ifndef CONTENT_BROWSER_LOADER_NAVIGATION_RESOURCE_HANDLER_H_
 #define CONTENT_BROWSER_LOADER_NAVIGATION_RESOURCE_HANDLER_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "content/browser/loader/resource_handler.h"
-#include "content/browser/loader/stream_writer.h"
+#include "content/browser/loader/layered_resource_handler.h"
+#include "content/public/browser/stream_handle.h"
 
 namespace net {
 class SSLInfo;
 }
 
 namespace content {
 class NavigationURLLoaderImplCore;
 class ResourceController;
 class ResourceDispatcherHostDelegate;
 struct SSLStatus;
 
-// PlzNavigate: The leaf ResourceHandler used with NavigationURLLoaderImplCore.
-class NavigationResourceHandler : public ResourceHandler {
+// PlzNavigate: The ResourceHandler used with NavigationURLLoaderImplCore to
+// control the flow of navigation requests.
+class NavigationResourceHandler : public LayeredResourceHandler {
  public:
   static void GetSSLStatusForRequest(const net::SSLInfo& ssl_info,
                                      SSLStatus* ssl_status);
 
   NavigationResourceHandler(
       net::URLRequest* request,
+      std::unique_ptr<ResourceHandler> next_handler,
       NavigationURLLoaderImplCore* core,
-      ResourceDispatcherHostDelegate* resource_dispatcher_host_delegate);
+      ResourceDispatcherHostDelegate* resource_dispatcher_host_delegate,
+      std::unique_ptr<StreamHandle> stream_handle);
   ~NavigationResourceHandler() override;
 
   // Called by the loader the cancel the request.
   void Cancel();
 
   // Called to the loader to resume a paused redirect.
   void FollowRedirect();
 
   // Called to proceed with the response.
   void ProceedWithResponse();
 
-  // ResourceHandler implementation.
+  // LayeredResourceHandler implementation.
   void OnRequestRedirected(
       const net::RedirectInfo& redirect_info,
       ResourceResponse* response,
       std::unique_ptr<ResourceController> controller) override;
   void OnResponseStarted(
       ResourceResponse* response,
       std::unique_ptr<ResourceController> controller) override;
-  void OnWillStart(const GURL& url,
-                   std::unique_ptr<ResourceController> controller) override;
-  void OnWillRead(scoped_refptr<net::IOBuffer>* buf,
-                  int* buf_size,
-                  std::unique_ptr<ResourceController> controller) override;
-  void OnReadCompleted(int bytes_read,
-                       std::unique_ptr<ResourceController> controller) override;
   void OnResponseCompleted(
       const net::URLRequestStatus& status,
       std::unique_ptr<ResourceController> controller) override;
-  void OnDataDownloaded(int bytes_downloaded) override;
 
  private:
   // Clears |core_| and its reference to the resource handler. After calling
   // this, the lifetime of the request is no longer managed by the
   // NavigationURLLoader.
   void DetachFromCore();
 
+  // Used to buffer the response and redirect info while waiting for UI thread
+  // checks to execute.
+  scoped_refptr<ResourceResponse> response_;
+  std::unique_ptr<net::RedirectInfo> redirect_info_;
+
   // NavigationResourceHandler has joint ownership of the
   // NavigationURLLoaderImplCore with the NavigationURLLoaderImpl.
   scoped_refptr<NavigationURLLoaderImplCore> core_;
-  StreamWriter writer_;
+  std::unique_ptr<StreamHandle> stream_handle_;
   ResourceDispatcherHostDelegate* resource_dispatcher_host_delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(NavigationResourceHandler);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_NAVIGATION_RESOURCE_HANDLER_H_