The default ping delay should be 90 seconds.

chrome/installer/util/master_preferences.cc

Index: chrome/installer/util/master_preferences.cc
diff --git a/chrome/installer/util/master_preferences.cc b/chrome/installer/util/master_preferences.cc
index 4ff8b2feab4f65a918e600d5482867b1aab78ddb..8a7c6375ef3b398222fd22ed66da3069e5ea9baf 100644
--- a/chrome/installer/util/master_preferences.cc
+++ b/chrome/installer/util/master_preferences.cc
@@ -79,6 +79,9 @@ const wchar_t kDistroImportHomePagePref[] = L"import_home_page";
 
 bool GetDistributionPingDelay(const FilePath& master_prefs_path,
                               int& delay) {
+  // 90 seconds is the default that we want to use in case master preferences
+  // is missing or corrupt.
+  delay = 90;
   FilePath master_prefs = master_prefs_path;
   if (master_prefs.empty()) {
     if (!PathService::Get(base::DIR_EXE, &master_prefs))