Added VLOG to trace the bug where switching users with both having...

Added VLOG to trace the bug where switching users with both having sunset-to-sunrise schedules may not apply NL correctly

Bug: 1015474
Change-Id: Ib8a92dad84563175a48bce1a5270b341716b15e9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1902114Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Commit-Queue: Jun Liu <yjliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#713678}

ash/system/night_light/night_light_controller_impl.cc

@@ -464,6 +464,21 @@ void NightLightControllerImpl::OnHostInitialized(aura::WindowTreeHost* host) {
 
 void NightLightControllerImpl::OnActiveUserPrefServiceChanged(
     PrefService* pref_service) {
+  // TODO(afakhry|yjliu): Remove this VLOG when https://crbug.com/1015474 is
+  // fixed.
+  auto vlog_helper = [](const PrefService* pref_service) -> std::string {
+    if (!pref_service)
+      return "None";
+    return base::StringPrintf(
+        "{State %s, Schedule Type: %d}",
+        pref_service->GetBoolean(prefs::kNightLightEnabled) ? "enabled"
+                                                            : "disabled",
+        pref_service->GetInteger(prefs::kNightLightScheduleType));
+  };
+  VLOG(1) << "Switching user pref service from "
+          << vlog_helper(active_user_pref_service_) << " to "
+          << vlog_helper(pref_service) << ".";
+
   // Initial login and user switching in multi profiles.
   active_user_pref_service_ = pref_service;
   InitFromUserPrefs();
@@ -608,6 +623,7 @@ void NightLightControllerImpl::NotifyClientWithScheduleChange() {
 }
 
 void NightLightControllerImpl::OnEnabledPrefChanged() {
+  VLOG(1) << "Enable state changed. New state: " << GetEnabled() << ".";
   DCHECK(active_user_pref_service_);
   Refresh(false /* did_schedule_change */);
   NotifyStatusChanged();
@@ -623,6 +639,7 @@ void NightLightControllerImpl::OnColorTemperaturePrefChanged() {
 }
 
 void NightLightControllerImpl::OnScheduleTypePrefChanged() {
+  VLOG(1) << "Schedule type changed. New type: " << GetScheduleType() << ".";
   DCHECK(active_user_pref_service_);
   NotifyClientWithScheduleChange();
   Refresh(true /* did_schedule_change */);