Extract the handling of the clean exit beacon from MetricsService. The extracted implementation sup…

components/metrics/metrics_service_client.h

 // Copyright 2014 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_METRICS_METRICS_SERVICE_CLIENT_H_
 #define COMPONENTS_METRICS_METRICS_SERVICE_CLIENT_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/callback_forward.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/strings/string16.h"
 #include "components/metrics/proto/system_profile.pb.h"
 
 namespace metrics {
 
 class MetricsLogUploader;
 
 // An abstraction of operations that depend on the embedder's (e.g. Chrome)
 // environment.
 class MetricsServiceClient {
  public:
@@ skipping 30 matching lines @@
   // extra histograms that will go in that log. Asynchronous API - the client
   // implementation should call |done_callback| when complete.
   virtual void CollectFinalMetrics(const base::Closure& done_callback) = 0;
 
   // Creates a MetricsLogUploader with the specified parameters (see comments on
   // MetricsLogUploader for details).
   virtual scoped_ptr<MetricsLogUploader> CreateUploader(
       const std::string& server_url,
       const std::string& mime_type,
       const base::Callback<void(int)>& on_upload_complete) = 0;
+
+  // Returns the name of a key under HKEY_CURRENT_USER that can be used to store
+  // backups of metrics data. Unused except on Windows.
+  virtual base::string16 GetRegistryBackupKey();
 };
 
 }  // namespace metrics
 
 #endif  // COMPONENTS_METRICS_METRICS_SERVICE_CLIENT_H_