Revert the 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_