4 files changed, 49 insertions, 5 deletions
diff --git a/chrome/browser/metrics/metrics_log.cc b/chrome/browser/metrics/metrics_log.cc
index 27cb88e..a504b11 100644
--- a/chrome/browser/metrics/metrics_log.cc
+++ b/chrome/browser/metrics/metrics_log.cc
@@ -280,7 +280,8 @@ void MetricsLog::EndElement() {
   DCHECK_GE(result, 0);
 }
 
-std::string MetricsLog::GetVersionString() const {
+// static
+std::string MetricsLog::GetVersionString() {
   scoped_ptr<FileVersionInfo> version_info(
       FileVersionInfo::CreateFileVersionInfoForCurrentModule());
   if (version_info.get()) {
diff --git a/chrome/browser/metrics/metrics_log.h b/chrome/browser/metrics/metrics_log.h
index 63ac23d..0f63538 100644
--- a/chrome/browser/metrics/metrics_log.h
+++ b/chrome/browser/metrics/metrics_log.h
@@ -103,6 +103,9 @@ class MetricsLog {
   // Return a base64-encoded MD5 hash of the given string.
   static std::string CreateBase64Hash(const std::string& string);
 
+  // Get the current version of the application as a string.
+  static std::string GetVersionString();
+
  protected:
   // Returns a string containing the current time.
   // Virtual so that it can be overridden for testing.
@@ -146,9 +149,6 @@ class MetricsLog {
   // Write the attributes that are common to every metrics event type.
   void WriteCommonEventAttributes();
 
-  // Get the current version of the application as a string.
-  std::string GetVersionString() const;
-
   // Returns the date at which the current metrics client ID was created as
   // a string containing milliseconds since the epoch, or "0" if none was found.
   std::string GetInstallDate() const;
diff --git a/chrome/browser/metrics/metrics_service.cc b/chrome/browser/metrics/metrics_service.cc
index 2906ef3..4d34ebb 100644
--- a/chrome/browser/metrics/metrics_service.cc
+++ b/chrome/browser/metrics/metrics_service.cc
@@ -306,6 +306,7 @@ void MetricsService::RegisterPrefs(PrefService* local_state) {
   local_state->RegisterStringPref(prefs::kStabilityLaunchTimeSec, L"0");
   local_state->RegisterStringPref(prefs::kStabilityLastTimestampSec, L"0");
   local_state->RegisterStringPref(prefs::kStabilityUptimeSec, L"0");
+  local_state->RegisterStringPref(prefs::kStabilityStatsVersion, L"");
   local_state->RegisterBooleanPref(prefs::kStabilityExitedCleanly, true);
   local_state->RegisterBooleanPref(prefs::kStabilitySessionEndCompleted, true);
   local_state->RegisterIntegerPref(prefs::kMetricsSessionID, -1);
@@ -336,6 +337,31 @@ void MetricsService::RegisterPrefs(PrefService* local_state) {
   local_state->RegisterListPref(prefs::kMetricsOngoingLogs);
 }
 
+// static
+void MetricsService::DiscardOldStabilityStats(PrefService* local_state) {
+  local_state->SetBoolean(prefs::kStabilityExitedCleanly, true);
+
+  local_state->SetInteger(prefs::kStabilityIncompleteSessionEndCount, 0);
+  local_state->SetInteger(prefs::kStabilityBreakpadRegistrationSuccess, 0);
+  local_state->SetInteger(prefs::kStabilityBreakpadRegistrationFail, 0);
+  local_state->SetInteger(prefs::kStabilityDebuggerPresent, 0);
+  local_state->SetInteger(prefs::kStabilityDebuggerNotPresent, 0);
+
+  local_state->SetInteger(prefs::kStabilityLaunchCount, 0);
+  local_state->SetInteger(prefs::kStabilityCrashCount, 0);
+
+  local_state->SetInteger(prefs::kStabilityPageLoadCount, 0);
+  local_state->SetInteger(prefs::kStabilityRendererCrashCount, 0);
+  local_state->SetInteger(prefs::kStabilityRendererHangCount, 0);
+
+  local_state->SetInteger(prefs::kSecurityRendererOnSboxDesktop, 0);
+  local_state->SetInteger(prefs::kSecurityRendererOnDefaultDesktop, 0);
+
+  local_state->SetString(prefs::kStabilityUptimeSec, L"0");
+
+  local_state->ClearPref(prefs::kStabilityPluginStats);
+}
+
 MetricsService::MetricsService()
     : recording_active_(false),
       reporting_active_(false),
@@ -550,6 +576,15 @@ void MetricsService::InitializeMetricsState() {
   PrefService* pref = g_browser_process->local_state();
   DCHECK(pref);
 
+  if (WideToUTF8(pref->GetString(prefs::kStabilityStatsVersion)) !=
+      MetricsLog::GetVersionString()) {
+    // This is a new version, so we don't want to confuse the stats about the
+    // old version with info that we upload.
+    DiscardOldStabilityStats(pref);
+    pref->SetString(prefs::kStabilityStatsVersion,
+                    UTF8ToWide(MetricsLog::GetVersionString()));
+  }
+
   client_id_ = WideToUTF8(pref->GetString(prefs::kMetricsClientID));
   if (client_id_.empty()) {
     client_id_ = GenerateClientID();
@@ -779,7 +814,7 @@ void MetricsService::PushPendingLogsToUnsentLists() {
       state_ = SEND_OLD_INITIAL_LOGS;
     } else {
       // TODO(jar): Verify correctness in other states, including sending unsent
-      // iniitial logs.
+      // initial logs.
       PushPendingLogTextToUnsentOngoingLogs();
     }
     DiscardPendingLog();
diff --git a/chrome/browser/metrics/metrics_service.h b/chrome/browser/metrics/metrics_service.h
index d42d953..630d2de 100644
--- a/chrome/browser/metrics/metrics_service.h
+++ b/chrome/browser/metrics/metrics_service.h
@@ -122,6 +122,14 @@ class MetricsService : public NotificationObserver,
   class GetPluginListTask;
   class GetPluginListTaskComplete;
 
+  // When we start a new version of Chromium (different from our last run), we
+  // need to discard the old crash stats so that we don't attribute crashes etc.
+  // in the old version to the current version (via current logs).
+  // Without this, a common reason to finally start a new version is to crash
+  // the old version (after an autoupdate has arrived), and so we'd bias
+  // initial results towards showing crashes :-(.
+  static void DiscardOldStabilityStats(PrefService* local_state);
+
   // Sets and gets whether metrics recording is active.
   // SetRecording(false) also forces a persistent save of logging state (if
   // anything has been recorded, or transmitted).