Revert r46023: "Detect new instance of the browser when running in the background in persistent"

chrome/installer/util/google_update_constants.h

Index: chrome/installer/util/google_update_constants.h
diff --git a/chrome/installer/util/google_update_constants.h b/chrome/installer/util/google_update_constants.h
index e21a19832ba214d3072d300d2251eea7d6579216..79100a66aedb3ae74752596bb2e7778259b3db98 100644
--- a/chrome/installer/util/google_update_constants.h
+++ b/chrome/installer/util/google_update_constants.h
@@ -46,6 +46,10 @@ extern const wchar_t kEnvProductVersionKey[];
 // last time that chrome ran in the Time internal format.
 extern const wchar_t kRegLastRunTimeField[];
 
+// How often to check if the persistent instance of Chrome needs to restart
+// to install an update.
+extern const int kUpdateCheckInvervalHours;
+
 }  // namespace google_update
 
 #endif  // CHROME_INSTALLER_UTIL_GOOGLE_UPDATE_CONSTANTS_H_