Daemonize (fork()) and install metrics_daemon in the image for execution.

src/platform/metrics_daemon/metrics_daemon.h

 // Copyright (c) 2009 The Chromium OS 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 METRICS_DAEMON_H_
 #define METRICS_DAEMON_H_
 
 #include <dbus/dbus-glib.h>
 #include <sys/time.h>
 #include <time.h>
 
 class MetricsDaemon {
 
  public:
   MetricsDaemon()
       : network_state_id_(kUnknownNetworkStateId), metrics_fd_(-1) {
   }
   ~MetricsDaemon() {}
 
-  // Does all the work.  If |testing| is true, log the stats instead of sending
-  // them to Chrome.
-  void Run(bool testing);
+  // Does all the work.  If |run_as_daemon| is true, daemonize by forking.  If
+  // |testing| is true, log the stats instead of sending them to Chrome.
+  void Run(bool run_as_daemon, bool testing);
 
  private:
   // Shared with Chrome for transport.
   static const char* kMetricsFilePath;
   static const int kMetricsMessageMaxLength = 4096;
 
   // The network states.  See network_states.h.
   typedef enum {
     // Initial/unknown network state id.
     kUnknownNetworkStateId = -1,
@@ skipping 47 matching lines @@
   // Array of network states of interest.
   static NetworkState network_states_[kNumberNetworkStates];
 
   bool testing_;                           // just testing
   NetworkStateId network_state_id_;        // id of current state
   struct timeval network_state_start_;     // when current state was entered
   int metrics_fd_;                         // for Chrome transport
 };
 
 #endif  // METRICS_DAEMON_H_