[subresource_filter] Add metrics for UI / related things

chrome/browser/subresource_filter/subresource_filter_content_settings_observer_factory.h

+// 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 CHROME_BROWSER_SUBRESOURCE_FILTER_SUBRESOURCE_FILTER_CONTENT_SETTINGS_OBSERVER_FACTORY_H_
+#define CHROME_BROWSER_SUBRESOURCE_FILTER_SUBRESOURCE_FILTER_CONTENT_SETTINGS_OBSERVER_FACTORY_H_
+
+#include "base/macros.h"
+#include "components/keyed_service/content/browser_context_keyed_service_factory.h"
+
+class KeyedService;
+class Profile;
+
+// This class is responsible for instantiating a profile-scoped object which
+// observes changes to content settings.
+class SubresourceFilterContentSettingsObserverFactory
+    : public BrowserContextKeyedServiceFactory {
+ public:
+  static void EnsureForProfile(Profile* profile);
+
+  static SubresourceFilterContentSettingsObserverFactory* GetInstance();
+
+  SubresourceFilterContentSettingsObserverFactory();
+
+ private:
+  KeyedService* BuildServiceInstanceFor(
+      content::BrowserContext* profile) const override;
+
+  DISALLOW_COPY_AND_ASSIGN(SubresourceFilterContentSettingsObserverFactory);
+};
+
+#endif  // CHROME_BROWSER_SUBRESOURCE_FILTER_SUBRESOURCE_FILTER_CONTENT_SETTINGS_OBSERVER_FACTORY_H_