Support needed to measure user and service traffic in Chrome.

components/data_use_measurement/core/data_use_user_data.h

Index: components/data_use_measurement/core/data_use_user_data.h
diff --git a/components/data_use_measurement/core/data_use_user_data.h b/components/data_use_measurement/core/data_use_user_data.h
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+++ b/components/data_use_measurement/core/data_use_user_data.h
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+// Copyright 2015 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_DATA_USE_MEASUREMENT_CORE_DATA_USE_USER_DATA_H_
+#define COMPONENTS_DATA_USE_MEASUREMENT_CORE_DATA_USE_USER_DATA_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "base/supports_user_data.h"
+
+namespace net {
+class URLFetcher;
+}
+
+namespace data_use_measurement {
+
+// Used to annotate URLRequests with the service name if the URLRequest is used
+// by a service.
+class DataUseUserData : public base::SupportsUserData::Data {
+ public:
+  // This enum should be synced with DataUseServices enum in histograms.xml.
+  // Please keep them synced after any updates. Also add service name to
+  // GetServiceNameAsString function.
+  enum ServiceName {
+    NOT_TAGGED,
+    SUGGESTIONS,
+  };
+
+  explicit DataUseUserData(ServiceName service_name);
+  ~DataUseUserData() override;
+
+  // Helper function to create DataUseUserData. The caller takes the ownership
+  // of the returned object.
+  static base::SupportsUserData::Data* Create(
+      DataUseUserData::ServiceName service);
+
+  // Return the service name of the ServiceName enum.
+  static std::string GetServiceNameAsString(ServiceName service);
+
+  // Services should use this function to attach their |service_name| to the
+  // URLFethcer serving them.
+  static void AttachToFetcher(net::URLFetcher* fetcher,
+                              ServiceName service_name);
+
+  ServiceName service_name() const { return service_name_; }
+
+  // The key for retrieving back this type of user data.
+  static const void* kUserDataKey;
+
+ private:
+  const ServiceName service_name_;
+
+  DISALLOW_COPY_AND_ASSIGN(DataUseUserData);
+};
+
+}  // data_use_measurement namespace
+
+#endif  // COMPONENTS_DATA_USE_MEASUREMENT_CORE_DATA_USE_USER_DATA_H_