Remove Startup Metrics preferences from incognito persistent whitelist.

Preferences related to Startup Metrics are removed from incognito
persistent storage list.

Bug: 861722
Change-Id: Id42fa05d2aabb38d4ec31dd01c012765d9f98d40
Reviewed-on: https://chromium-review.googlesource.com/1166827Reviewed-by: François Doray <fdoray@chromium.org>
Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582832}

chrome/browser/prefs/pref_service_incognito_whitelist.cc

@@ -25,7 +25,6 @@
 #include "components/rappor/rappor_pref_names.h"
 #include "components/reading_list/core/reading_list_pref_names.h"
 #include "components/search_engines/search_engines_pref_names.h"
-#include "components/startup_metric_utils/browser/pref_names.h"
 #include "components/suggestions/suggestions_pref_names.h"
 #include "components/ukm/ukm_pref_names.h"
 #include "components/variations/pref_names.h"
@@ -811,11 +810,6 @@ const char* temporary_incognito_whitelist[] = {
     prefs::kDefaultSearchProviderEnabled, prefs::kSearchProviderOverrides,
     prefs::kSearchProviderOverridesVersion, prefs::kCountryIDAtInstall,
 
-    // components/startup_metric_utils/browser/pref_names.h
-    startup_metric_utils::prefs::kLastStartupTimestamp,
-    startup_metric_utils::prefs::kLastStartupVersion,
-    startup_metric_utils::prefs::kSameVersionStartupCount,
-
     // components/suggestions/suggestions_pref_names.h
     suggestions::prefs::kSuggestionsBlacklist,
     suggestions::prefs::kSuggestionsData,