Add the client for accessing Subresource Filter only list.

components/subresource_filter/content/browser/subresource_filter_safe_browsing_activation_throttle.h

+// Copyright (c) 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 "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "base/single_thread_task_runner.h"
+#include "components/safe_browsing_db/database_manager.h"
+#include "content/public/browser/navigation_throttle.h"
+#include "url/gurl.h"
+
+namespace subresource_filter {
+
+// 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,
+      scoped_refptr<safe_browsing::SafeBrowsingDatabaseManager>
+          database_manager);
+
+  ~SubresourceFilterSafeBrowsingActivationThrottle() override;
+
+  // content::NavigationThrottle:
+  content::NavigationThrottle::ThrottleCheckResult WillProcessResponse()
+      override;
+
+  void OnCheckUrlResultOnUI(const GURL& url,
+                            safe_browsing::SBThreatType threat_type,
+                            safe_browsing::ThreatPatternType pattern_type);
+
+ private:
+  class SBDatabaseClient;
+
+  scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
+  std::unique_ptr<SBDatabaseClient, base::OnTaskRunnerDeleter> database_client_;
+
+  DISALLOW_COPY_AND_ASSIGN(SubresourceFilterSafeBrowsingActivationThrottle);
+};
+
+}  // namespace subresource_filter
+
+#endif  // COMPONENTS_SUBRESOURCE_FILTER_CONTENT_BROWSER_SUBRESOURCE_FILTER_SAFE_BROWSING_ACTIVATION_THROTTLE_H_