[subresource_filter] Add metrics for UI / related things

chrome/browser/subresource_filter/subresource_filter_content_settings_observer_factory.cc

+// 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.
+
+#include "chrome/browser/subresource_filter/subresource_filter_content_settings_observer_factory.h"
+
+#include <string>
+
+#include "base/logging.h"
+#include "chrome/browser/content_settings/host_content_settings_map_factory.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/subresource_filter/chrome_subresource_filter_client.h"
+#include "components/content_settings/core/browser/content_settings_details.h"
+#include "components/content_settings/core/browser/content_settings_observer.h"
+#include "components/content_settings/core/browser/host_content_settings_map.h"
+#include "components/content_settings/core/common/content_settings.h"
+#include "components/content_settings/core/common/content_settings_pattern.h"
+#include "components/content_settings/core/common/content_settings_types.h"
+#include "components/keyed_service/content/browser_context_dependency_manager.h"
+#include "components/keyed_service/core/keyed_service.h"
+#include "url/gurl.h"
+
+namespace {
+
+void LogActionForContentSettingChange(
+    ContentSetting setting,
+    SubresourceFilterAction action_for_block,
+    SubresourceFilterAction action_for_allow) {
+  switch (setting) {
+    case CONTENT_SETTING_BLOCK:
+      ChromeSubresourceFilterClient::LogSubresourceFilterAction(
+          action_for_block);
+      break;
+    case CONTENT_SETTING_ALLOW:
+      ChromeSubresourceFilterClient::LogSubresourceFilterAction(
+          action_for_allow);
+      break;
+    case CONTENT_SETTING_DEFAULT:
+    case CONTENT_SETTING_ASK:
+    case CONTENT_SETTING_SESSION_ONLY:
+    case CONTENT_SETTING_DETECT_IMPORTANT_CONTENT:
+    case CONTENT_SETTING_NUM_SETTINGS:
+      NOTREACHED();
+      break;
+  }
+}
+
+// This class observers subresource filter content settings changes for metrics
+// collection.
+//
+// TODO(csharrison): Consider moving this class to its own file if the
+// subresource filter needs to keep other profile-scoped state.
+class SubresourceFilterContentSettingsObserver
+    : public KeyedService,
+      public content_settings::Observer {
+ public:
+  explicit SubresourceFilterContentSettingsObserver(Profile* profile)
+      : settings_map_(HostContentSettingsMapFactory::GetForProfile(profile)) {
+    DCHECK(profile);
+    DCHECK(settings_map_);
+    settings_map_->AddObserver(this);
+  }
+
+  ~SubresourceFilterContentSettingsObserver() override {}
+
+ private:
+  // KeyedService:
+  void Shutdown() override {
+    settings_map_->RemoveObserver(this);
+    settings_map_ = nullptr;
+  }
+
+  // content_settings::Observer:
+  void OnContentSettingChanged(const ContentSettingsPattern& primary_pattern,
+                               const ContentSettingsPattern& secondary_pattern,
+                               ContentSettingsType content_type,
+                               std::string resource_identifier) override {
+    if (content_type != CONTENT_SETTINGS_TYPE_SUBRESOURCE_FILTER)
+      return;
+
+    const ContentSettingsDetails details(primary_pattern, secondary_pattern,
+                                         content_type, resource_identifier);
+    if (details.update_all()) {

[msramek, 2017/03/29 17:37:30]

To your question, yes, DefaultProvider apparently sends empty (and thus invalid)
patterns instead of Wildcards()s when a default setting is updated. That seems
like a remnant of some very old design choice... But your solution should be
correct.

+      ContentSetting global_setting = settings_map_->GetDefaultContentSetting(
+          CONTENT_SETTINGS_TYPE_SUBRESOURCE_FILTER, nullptr);
+      LogActionForContentSettingChange(global_setting,
+                                       kActionContentSettingsBlockedGlobal,
+                                       kActionContentSettingsAllowedGlobal);
+      return;
+    }
+
+    // Remove this DCHECK if extension APIs or admin policies are given the
+    // ability to set secondary patterns for this setting.
+    DCHECK(secondary_pattern == ContentSettingsPattern::Wildcard());
+
+    DCHECK(primary_pattern.IsValid());
+
+    // An invalid URL indicates that this is a wildcard pattern.
+    GURL url = GURL(primary_pattern.ToString());
+    if (!url.is_valid()) {
+      ChromeSubresourceFilterClient::LogSubresourceFilterAction(
+          kActionContentSettingsWildcardUpdate);
+      return;
+    }
+
+    ContentSetting setting = settings_map_->GetContentSetting(
+        url, url, ContentSettingsType::CONTENT_SETTINGS_TYPE_SUBRESOURCE_FILTER,
+        std::string());
+    LogActionForContentSettingChange(setting, kActionContentSettingsBlocked,
+                                     kActionContentSettingsAllowed);
+  }
+
+  HostContentSettingsMap* settings_map_;
+
+  DISALLOW_COPY_AND_ASSIGN(SubresourceFilterContentSettingsObserver);
+};
+
+}  // namespace
+
+// static
+void SubresourceFilterContentSettingsObserverFactory::EnsureForProfile(
+    Profile* profile) {
+  GetInstance()->GetServiceForBrowserContext(profile, true /* create */);
+}
+
+// static
+SubresourceFilterContentSettingsObserverFactory*
+SubresourceFilterContentSettingsObserverFactory::GetInstance() {
+  return base::Singleton<
+      SubresourceFilterContentSettingsObserverFactory>::get();
+}
+
+SubresourceFilterContentSettingsObserverFactory::
+    SubresourceFilterContentSettingsObserverFactory()
+    : BrowserContextKeyedServiceFactory(
+          "SubresourceFilterContentSettingsObserver",
+          BrowserContextDependencyManager::GetInstance()) {}
+
+KeyedService*
+SubresourceFilterContentSettingsObserverFactory::BuildServiceInstanceFor(
+    content::BrowserContext* profile) const {
+  return new SubresourceFilterContentSettingsObserver(
+      static_cast<Profile*>(profile));
+}