http://codereview.chromium.org/147084...

chrome/browser/metrics/metrics_service.h

 // Copyright (c) 2006-2008 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.
 
 // This file defines a service that collects information about the user
 // experience in order to help improve future versions of the app.
 
 #ifndef CHROME_BROWSER_METRICS_SERVICE_H_
 #define CHROME_BROWSER_METRICS_SERVICE_H_
 
 #include <list>
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/histogram.h"
 #include "base/scoped_ptr.h"
 #include "base/values.h"
 #include "chrome/browser/metrics/metrics_log.h"
 #include "chrome/browser/net/url_fetcher.h"
 #include "chrome/common/notification_registrar.h"
 #include "webkit/glue/webplugin.h"
+#include "testing/gtest/include/gtest/gtest_prod.h"
 
 class BookmarkModel;
 class BookmarkNode;
 class HistogramSynchronizer;
 class PrefService;
 class Profile;
 class TemplateURLModel;
 
 // This is used to quickly log stats from child process related notifications in
 // MetricsService::child_stats_buffer_.  The buffer's contents are transferred
@@ skipping 118 matching lines @@
   // idle_since_last_transmission to false and starts the timer (provided
   // starting the timer is permitted).
   void HandleIdleSinceLastTransmission(bool in_idle);
 
   // Set up client ID, session ID, etc.
   void InitializeMetricsState();
 
   // Generates a new client ID to use to identify self to metrics server.
   static std::string GenerateClientID();
 
+#if defined(OS_POSIX)
+  // Generates a new client ID to use to identify self to metrics server,
+  // given 128 bits of randomness.
+  static std::string RandomBytesToGUIDString(const uint64 bytes[2]);
+#endif
+
   // Schedule the next save of LocalState information.  This is called
   // automatically by the task that performs each save to schedule the next one.
   void ScheduleNextStateSave();
 
   // Save the LocalState information immediately. This should not be called by
   // anybody other than the scheduler to avoid doing too many writes. When you
   // make a change, call ScheduleNextStateSave() instead.
   void SaveLocalState();
 
   // Called to start recording user experience metrics.
@@ skipping 295 matching lines @@
   // The types of data that are to be included in the logs and histograms
   // according to the UMA response data.
   std::set<std::string> logs_to_upload_;
   std::set<std::string> logs_to_omit_;
   std::set<std::string> histograms_to_upload_;
   std::set<std::string> histograms_to_omit_;
 
   // Indicate that a timer for sending the next log has already been queued.
   bool timer_pending_;
 
+  FRIEND_TEST(MetricsServiceTest, ClientIdGeneratesAllZeroes);
+  FRIEND_TEST(MetricsServiceTest, ClientIdGeneratesCorrectly);
+  FRIEND_TEST(MetricsServiceTest, ClientIdCorrectlyFormatted);
   DISALLOW_COPY_AND_ASSIGN(MetricsService);
 };
 
 #endif  // CHROME_BROWSER_METRICS_SERVICE_H_