Resetting metrics ids on clump detection.

chrome/browser/metrics/cloned_install_detector.cc

Index: chrome/browser/metrics/cloned_install_detector.cc
diff --git a/chrome/browser/metrics/cloned_install_detector.cc b/chrome/browser/metrics/cloned_install_detector.cc
index 3ecfd2ccea742a6e4a0d5c52cf70f0b7ddc5f6c9..669ec60829e18e272e6ec21efaf4e56a8d4f18d3 100644
--- a/chrome/browser/metrics/cloned_install_detector.cc
+++ b/chrome/browser/metrics/cloned_install_detector.cc
@@ -49,7 +49,8 @@ ClonedInstallDetector::ClonedInstallDetector(MachineIdProvider* raw_id_provider)
 ClonedInstallDetector::~ClonedInstallDetector() {}
 
 void ClonedInstallDetector::CheckForClonedInstall(PrefService* local_state) {
-  content::BrowserThread::PostTaskAndReplyWithResult(
+  DVLOG(2) << "\n\nabout to post some tasks.\n\n";
+  bool res = content::BrowserThread::PostTaskAndReplyWithResult(
       content::BrowserThread::FILE,
       FROM_HERE,
       base::Bind(&metrics::MachineIdProvider::GetMachineId,
@@ -57,11 +58,13 @@ void ClonedInstallDetector::CheckForClonedInstall(PrefService* local_state) {
       base::Bind(&metrics::ClonedInstallDetector::SaveMachineId,
                  weak_ptr_factory_.GetWeakPtr(),
                  local_state));
+  DVLOG(2) << "\n\ntask posted? " << res << "\n\n";
 }
 
 void ClonedInstallDetector::SaveMachineId(
     PrefService* local_state,
     std::string raw_id) {
+  DVLOG(2) << "\n\nsaving id: " << raw_id << "\n\n";
   if (raw_id.empty()) {
     LogMachineIdState(ID_GENERATION_FAILED);
     local_state->ClearPref(prefs::kMetricsMachineId);
@@ -72,8 +75,12 @@ void ClonedInstallDetector::SaveMachineId(
 
   MachineIdState id_state = ID_NO_STORED_VALUE;
   if (local_state->HasPrefPath(prefs::kMetricsMachineId)) {
-    id_state = local_state->GetInteger(prefs::kMetricsMachineId) == hashed_id ?
-        ID_UNCHANGED : ID_CHANGED;
+    if (local_state->GetInteger(prefs::kMetricsMachineId) != hashed_id) {
+      id_state = ID_CHANGED;
+      local_state->SetBoolean(prefs::kMetricsResetIds, true);

[Alexei Svitkine (slow), 2014/03/28 16:30:48]

Can this be a callback passed to this class at construction time? That way,
MetricsService can be the one to reset the pref.

(I'm okay with making this a TODO for this CL, though.)

[jwd, 2014/03/28 18:59:21]

Done.

+    } else {
+      id_state = ID_UNCHANGED;
+    }
   }
 
   LogMachineIdState(id_state);