Reland "Merge of CrossSiteResourceHandler and NavigationResourceThrottle."

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/macros.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 {
-
-struct TransitionLayerData;
-
-// Ensures that responses are delayed for navigations that must be transferred
-// to a different process.  This handler wraps an AsyncEventHandler, and it sits
-// inside SafeBrowsing and Buffered event handlers.  This is important, so that
-// it can intercept OnResponseStarted after we determine that a response is safe
-// and not a download.
-class CrossSiteResourceHandler : public LayeredResourceHandler {
- public:
-  enum class NavigationDecision {
-    TRANSFER_REQUIRED,
-    USE_EXISTING_RENDERER,
-    CANCEL_REQUEST
-  };
-
-  CrossSiteResourceHandler(std::unique_ptr<ResourceHandler> next_handler,
-                           net::URLRequest* request);
-  ~CrossSiteResourceHandler() override;
-
-  // ResourceHandler implementation:
-  bool OnRequestRedirected(const net::RedirectInfo& redirect_info,
-                           ResourceResponse* response,
-                           bool* defer) override;
-  bool OnResponseStarted(ResourceResponse* response, bool* defer) override;
-  bool OnReadCompleted(int bytes_read, bool* defer) override;
-  void OnResponseCompleted(const net::URLRequestStatus& status,
-                           bool* defer) override;
-
-  // We can now send the response to the new renderer, which will cause
-  // WebContentsImpl to swap in the new renderer and destroy the old one.
-  void ResumeResponse();
-
-  // When set to true, requests are leaked when they can't be passed to a
-  // RenderViewHost, for unit tests.
-  CONTENT_EXPORT static void SetLeakRequestsForTesting(
-      bool leak_requests_for_testing);
-
- private:
-  // Prepare to transfer the cross-site response to a new RenderFrameHost, by
-  // asking it to issue an identical request (on the UI thread).
-  void StartCrossSiteTransition(ResourceResponse* response);
-
-  // Defer the navigation to the UI thread to check whether transfer is required
-  // or not. Currently only used in --site-per-process.
-  bool DeferForNavigationPolicyCheck(ResourceRequestInfoImpl* info,
-                                     ResourceResponse* response,
-                                     bool* defer);
-
-  bool OnNormalResponseStarted(ResourceResponse* response,
-                               bool* defer);
-
-  void ResumeOrTransfer(NavigationDecision decision);
-  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_;
-  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_