Allows prefetch requests to live beyond the renderer by delaying

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 "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
+#include "base/timer/timer.h"
 #include "content/browser/loader/resource_handler.h"
 #include "content/browser/ssl/ssl_error_handler.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/resource_controller.h"
 #include "net/url_request/url_request.h"
 
 namespace content {
 class ResourceDispatcherHostLoginDelegate;
 class ResourceLoaderDelegate;
 class ResourceRequestInfoImpl;
 class SSLClientAuthHandler;
 
 // 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 ResourceController {
  public:
   ResourceLoader(scoped_ptr<net::URLRequest> request,
                  scoped_ptr<ResourceHandler> handler,
                  ResourceLoaderDelegate* delegate);
   virtual ~ResourceLoader();
 
   void StartRequest();
   void CancelRequest(bool from_renderer);
 
+  // Sets the resource as detached and starts a timer to cancel the request in
+  // the future.
+  void Detach();
+
   void ReportUploadProgress();
 
   bool is_transferring() const { return is_transferring_; }
   void MarkAsTransferring(const GURL& target_url);
   void CompleteTransfer();
 
   net::URLRequest* request() { return request_.get(); }
   ResourceRequestInfoImpl* GetRequestInfo();
 
   void ClearLoginDelegate();
   void ClearSSLClientAuthHandler();
 
   // IPC message handlers:
   void OnUploadProgressACK();
 
+  void set_detachable_delay_ms(int delay) {
+    detachable_delay_on_cancel_ms_ = delay;
+  }
+
  private:
   FRIEND_TEST_ALL_PREFIXES(ResourceLoaderTest, ClientCertStoreLookup);
   FRIEND_TEST_ALL_PREFIXES(ResourceLoaderTest, ClientCertStoreNull);
 
   // net::URLRequest::Delegate implementation:
   virtual void OnReceivedRedirect(net::URLRequest* request,
                                   const GURL& new_url,
                                   bool* defer) OVERRIDE;
   virtual void OnAuthRequired(net::URLRequest* request,
                               net::AuthChallengeInfo* info) OVERRIDE;
@@ skipping 49 matching lines @@
   uint64 last_upload_position_;
   bool waiting_for_upload_progress_ack_;
   base::TimeTicks last_upload_ticks_;
   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_;
 
+  int detachable_delay_on_cancel_ms_;
+  scoped_ptr<base::OneShotTimer<ResourceLoader> > detached_timer_;
+
   base::WeakPtrFactory<ResourceLoader> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourceLoader);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_RESOURCE_LOADER_H_