[subresource_filter] SB throttle can send multiple speculative requests.

components/subresource_filter/content/browser/subresource_filter_safe_browsing_activation_throttle.h

-// Copyright (c) 2017 The Chromium Authors. All rights reserved.
+// Copyright 2017 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 COMPONENTS_SUBRESOURCE_FILTER_CONTENT_BROWSER_SUBRESOURCE_FILTER_SAFE_BROWSING_ACTIVATION_THROTTLE_H_
 #define COMPONENTS_SUBRESOURCE_FILTER_CONTENT_BROWSER_SUBRESOURCE_FILTER_SAFE_BROWSING_ACTIVATION_THROTTLE_H_
 
+#include <memory>
+
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/single_thread_task_runner.h"
+#include "base/time/time.h"
 #include "components/safe_browsing_db/database_manager.h"
 #include "content/public/browser/navigation_throttle.h"
-#include "url/gurl.h"
+
+class GURL;
+
+namespace base {
+class Timer;
+}  // namespace base
 
 namespace subresource_filter {
 
+class SubresourceFilterSafeBrowsingClient;
+
 // Navigation throttle responsible for activating subresource filtering on page
 // loads that match the SUBRESOURCE_FILTER Safe Browsing list.
 class SubresourceFilterSafeBrowsingActivationThrottle
     : public content::NavigationThrottle,
       public base::SupportsWeakPtr<
           SubresourceFilterSafeBrowsingActivationThrottle> {
  public:
   SubresourceFilterSafeBrowsingActivationThrottle(
       content::NavigationHandle* handle,
+      std::unique_ptr<base::Timer> timer,
       scoped_refptr<safe_browsing::SafeBrowsingDatabaseManager>
           database_manager);
 
   ~SubresourceFilterSafeBrowsingActivationThrottle() override;
 
   // content::NavigationThrottle:
+  content::NavigationThrottle::ThrottleCheckResult WillStartRequest() override;
+  content::NavigationThrottle::ThrottleCheckResult WillRedirectRequest()
+      override;
   content::NavigationThrottle::ThrottleCheckResult WillProcessResponse()
       override;
 
   void OnCheckUrlResultOnUI(const GURL& url,
+                            int request_id,
                             safe_browsing::SBThreatType threat_type,
                             safe_browsing::ThreatPatternType pattern_type);
 
  private:
-  class SBDatabaseClient;
+  void CheckUrl();
+  void NotifyResult();
 
+  scoped_refptr<safe_browsing::SafeBrowsingDatabaseManager> database_manager_;
   scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
-  std::unique_ptr<SBDatabaseClient, base::OnTaskRunnerDeleter> database_client_;
+
+  int current_request_id_ = 0;
+  int last_received_request_id_ = 0;
+
+  // Cached check results to be forwarded in WillProessResponse.
+  safe_browsing::SBThreatType threat_type_ =
+      safe_browsing::SBThreatType::SB_THREAT_TYPE_SAFE;
+  safe_browsing::ThreatPatternType pattern_type_ =
+      safe_browsing::ThreatPatternType::NONE;
+
+  std::unique_ptr<SubresourceFilterSafeBrowsingClient,
+                  base::OnTaskRunnerDeleter>
+      database_client_;
+
+  // Set to TimeTicks::Now() when the navigation is deferred in
+  // WillProcessResponse. If deferral was not necessary, will remain null.
+  base::TimeTicks defer_time_;
 
   DISALLOW_COPY_AND_ASSIGN(SubresourceFilterSafeBrowsingActivationThrottle);
 };
 
 }  // namespace subresource_filter
 
 #endif  // COMPONENTS_SUBRESOURCE_FILTER_CONTENT_BROWSER_SUBRESOURCE_FILTER_SAFE_BROWSING_ACTIVATION_THROTTLE_H_