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      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef CONTENT_BROWSER_LOADER_CROSS_SITE_RESOURCE_HANDLER_H_
      6 #define CONTENT_BROWSER_LOADER_CROSS_SITE_RESOURCE_HANDLER_H_
      7 
      8 #include "base/memory/ref_counted.h"
      9 #include "base/memory/weak_ptr.h"
     10 #include "content/browser/loader/layered_resource_handler.h"
     11 #include "content/common/content_export.h"
     12 #include "net/url_request/url_request_status.h"
     13 
     14 namespace net {
     15 class URLRequest;
     16 }
     17 
     18 namespace content {
     19 
     20 struct TransitionLayerData;
     21 
     22 // Ensures that responses are delayed for navigations that must be transferred
     23 // to a different process.  This handler wraps an AsyncEventHandler, and it sits
     24 // inside SafeBrowsing and Buffered event handlers.  This is important, so that
     25 // it can intercept OnResponseStarted after we determine that a response is safe
     26 // and not a download.
     27 class CrossSiteResourceHandler : public LayeredResourceHandler {
     28  public:
     29   CrossSiteResourceHandler(scoped_ptr<ResourceHandler> next_handler,
     30                            net::URLRequest* request);
     31   virtual ~CrossSiteResourceHandler();
     32 
     33   // ResourceHandler implementation:
     34   virtual bool OnRequestRedirected(const net::RedirectInfo& redirect_info,
     35                                    ResourceResponse* response,
     36                                    bool* defer) OVERRIDE;
     37   virtual bool OnResponseStarted(ResourceResponse* response,
     38                                  bool* defer) OVERRIDE;
     39   virtual bool OnReadCompleted(int bytes_read,
     40                                bool* defer) OVERRIDE;
     41   virtual void OnResponseCompleted(const net::URLRequestStatus& status,
     42                                    const std::string& security_info,
     43                                    bool* defer) OVERRIDE;
     44 
     45   // We can now send the response to the new renderer, which will cause
     46   // WebContentsImpl to swap in the new renderer and destroy the old one.
     47   void ResumeResponse();
     48 
     49   // When set to true, requests are leaked when they can't be passed to a
     50   // RenderViewHost, for unit tests.
     51   CONTENT_EXPORT static void SetLeakRequestsForTesting(
     52       bool leak_requests_for_testing);
     53 
     54   // Navigations are deferred at OnResponseStarted to parse out any navigation
     55   // transition link headers, and give the navigation transition (if it exists)
     56   // a chance to run.
     57   void ResumeResponseDeferredAtStart(int request_id);
     58 
     59   // Returns whether the handler is deferred.
     60   bool did_defer_for_testing() const { return did_defer_; }
     61 
     62  private:
     63   // Prepare to transfer the cross-site response to a new RenderFrameHost, by
     64   // asking it to issue an identical request (on the UI thread).
     65   void StartCrossSiteTransition(ResourceResponse* response);
     66 
     67   // Defer the navigation to the UI thread to check whether transfer is required
     68   // or not. Currently only used in --site-per-process.
     69   bool DeferForNavigationPolicyCheck(ResourceRequestInfoImpl* info,
     70                                      ResourceResponse* response,
     71                                      bool* defer);
     72 
     73   bool OnNavigationTransitionResponseStarted(
     74       ResourceResponse* response,
     75       bool* defer,
     76       const TransitionLayerData& transition_data);
     77 
     78   bool OnNormalResponseStarted(ResourceResponse* response,
     79                                bool* defer);
     80 
     81   void ResumeOrTransfer(bool is_transfer);
     82   void ResumeIfDeferred();
     83 
     84   // Called when about to defer a request.  Sets |did_defer_| and logs the
     85   // defferral
     86   void OnDidDefer();
     87 
     88   bool has_started_response_;
     89   bool in_cross_site_transition_;
     90   bool completed_during_transition_;
     91   bool did_defer_;
     92   net::URLRequestStatus completed_status_;
     93   std::string completed_security_info_;
     94   scoped_refptr<ResourceResponse> response_;
     95 
     96   // TODO(nasko): WeakPtr is needed in --site-per-process, since all navigations
     97   // are deferred to the UI thread and come back to IO thread via
     98   // PostTaskAndReplyWithResult. If a transfer is needed, it goes back to the UI
     99   // thread. This can be removed once the code is changed to only do one hop.
    100   base::WeakPtrFactory<CrossSiteResourceHandler> weak_ptr_factory_;
    101 
    102   DISALLOW_COPY_AND_ASSIGN(CrossSiteResourceHandler);
    103 };
    104 
    105 }  // namespace content
    106 
    107 #endif  // CONTENT_BROWSER_LOADER_CROSS_SITE_RESOURCE_HANDLER_H_
    108