When we upgrade, discard all uploadable stats, including old logs...

chrome/browser/metrics/metrics_service.cc

Index: chrome/browser/metrics/metrics_service.cc
===================================================================
--- chrome/browser/metrics/metrics_service.cc	(revision 18545)
+++ chrome/browser/metrics/metrics_service.cc	(working copy)
@@ -372,6 +372,14 @@
   local_state->SetString(prefs::kStabilityUptimeSec, L"0");
 
   local_state->ClearPref(prefs::kStabilityPluginStats);
+
+  ListValue* unsent_initial_logs = local_state->GetMutableList(
+      prefs::kMetricsInitialLogs);
+  unsent_initial_logs->Clear();
+
+  ListValue* unsent_ongoing_logs = local_state->GetMutableList(
+      prefs::kMetricsOngoingLogs);

[Evan Martin, 2009/06/19 05:14:22]

Can these ever be NULL?  Just want you to be sure.

[jar (doing other things), 2009/06/19 06:07:22]

It is guaranteed to be non-NULL so long as the pref is registered.  It will
create a dictionary if one does not exist, or return the existing dictionary.

All prefs are registered in a local function MetricsService::RegisterPrefs()
which is one of many module initialization functions called from
RegisterAllPrefs() in browser_prefs.cc.   Bottom line: The prefs are registered
whether metrics services are used or not, and hence this return value is always
non-NULL.

+  unsent_ongoing_logs->Clear();
 }
 
 MetricsService::MetricsService()