Add the client for accessing Subresource Filter only list.

components/subresource_filter/content/browser/subresource_filter_activation_navigation_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_ACTIVATION_RESOURCE_THROTTLE_H_
+#define COMPONENTS_SUBRESOURCE_FILTER_CONTENT_BROWSER_SUBRESOURCE_FILTER_ACTIVATION_RESOURCE_THROTTLE_H_
+
+#include <string>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/time/time.h"

[engedy, 2017/02/17 20:50:52]

nit: Unused include.

[melandory, 2017/02/28 12:16:05]

Done.

+#include "base/timer/timer.h"
+#include "components/safe_browsing_db/database_manager.h"
+#include "content/public/browser/navigation_throttle.h"
+#include "url/gurl.h"
+
+namespace subresource_filter {
+
+// Client for accessing list with patterns to be used by the Subresource Filter.
+class SubresourceFilterActivationNavigationThrottle

[engedy, 2017/02/17 20:50:53]

For disambiguation from other throttles, we should call this either
SafeBrowsingSubresourceFilterActivationThrottle or
SubresourceFilterSafeBrowsingActivationThrottle.

[melandory, 2017/02/28 12:16:05]

Done.

+    : public content::NavigationThrottle,
+      public safe_browsing::SafeBrowsingDatabaseManager::Client,
+      public base::SupportsWeakPtr<
+          SubresourceFilterActivationNavigationThrottle> {
+ public:
+  SubresourceFilterActivationNavigationThrottle(
+      content::NavigationHandle* handle,
+      const scoped_refptr<safe_browsing::SafeBrowsingDatabaseManager>&
+          database_manager);
+
+  ~SubresourceFilterActivationNavigationThrottle() override;
+
+  content::NavigationThrottle::ThrottleCheckResult WillProcessResponse()

[engedy, 2017/02/17 20:50:53]

nit: Add above this line:

 // content::NavigaionThrottle:

[melandory, 2017/02/28 12:16:05]

Done.

+      override;
+
+  // SafeBrowsingDabaseManager::Client implementation (called on IO thread):
+  void OnCheckBrowseUrlResult(

[engedy, 2017/02/17 20:50:53]

As discussed off-line, we will have to introduce an object to proxy these calls
and receive the results from the SBDatabaseManager on the IO thread. The easiest
seems to be make this object live on the IO thread with the DeleteSoon idiom,
and make it PostTask to this throttle using a WeakPtr to it.

[melandory, 2017/02/28 12:16:05]

Done.

+      const GURL& url,
+      safe_browsing::SBThreatType result,
+      const safe_browsing::ThreatMetadata& metadata) override;
+
+ private:
+  // Callback for when the safe browsing check has taken longer than
+  // kCheckUrlTimeoutMs.
+  void OnCheckUrlTimeout();
+
+  void CheckUrlOnIO(const GURL& url);
+
+  void OnCheckUrlResultOnUI(const GURL& url,
+                            safe_browsing::SBThreatType threat_type,
+                            safe_browsing::ThreatPatternType pattern_type);
+
+  // Timer to abort the safe browsing check if it takes too long.
+  base::OneShotTimer timer_;
+
+  scoped_refptr<safe_browsing::SafeBrowsingDatabaseManager> database_manager_;
+
+  GURL url_being_checked_;
+
+  DISALLOW_COPY_AND_ASSIGN(SubresourceFilterActivationNavigationThrottle);
+};
+
+}  // namespace subresource_filter
+
+#endif  // COMPONENTS_SUBRESOURCE_FILTER_CONTENT_BROWSER_SUBRESOURCE_FILTER_ACTIVATION_RESOURCE_THROTTLE_H_