Adding Finch and flag for Sign-in promo

components/signin/core/common/signin_switches.cc

Index: components/signin/core/common/signin_switches.cc
diff --git a/components/signin/core/common/signin_switches.cc b/components/signin/core/common/signin_switches.cc
index 0473a9a5d0f2533d798950b406b582b70a6f80c9..f31bc2c7010dc89f0652bd77e3abfeb6d1277778 100644
--- a/components/signin/core/common/signin_switches.cc
+++ b/components/signin/core/common/signin_switches.cc
@@ -10,6 +10,9 @@ namespace switches {
 // expiration of credentials during testing.
 const char kClearTokenService[] = "clear-token-service";
 
+// Disables sign-in promo.
+const char kDisableSigninPromo[] = "disable-signin-promo";
+
 // Disables sending signin scoped device id to LSO with refresh token request.
 const char kDisableSigninScopedDeviceId[] = "disable-signin-scoped-device-id";
 
@@ -20,6 +23,9 @@ const char kEnableAccountConsistency[] = "enable-account-consistency";
 extern const char kEnableRefreshTokenAnnotationRequest[] =
     "enable-refresh-token-annotation-request";
 
+// Enables sign-in promo.
+const char kEnableSigninPromo[] = "enable-signin-promo";
+
 // Enables multiple account versions of chrome.identity APIs.
 const char kExtensionsMultiAccount[] = "extensions-multi-account";