Adding ChromeIdentity in ShowSigninCommand.

ios/chrome/browser/ui/commands/show_signin_command.h

Index: ios/chrome/browser/ui/commands/show_signin_command.h
diff --git a/ios/chrome/browser/ui/commands/show_signin_command.h b/ios/chrome/browser/ui/commands/show_signin_command.h
index d5bb99c3d10cbbd91ac786ac627179bc2922d094..40f97d491ca548868b05fcc85b851843eaa7212f 100644
--- a/ios/chrome/browser/ui/commands/show_signin_command.h
+++ b/ios/chrome/browser/ui/commands/show_signin_command.h
@@ -10,6 +10,8 @@
 #include "components/signin/core/browser/signin_metrics.h"
 #include "ios/chrome/browser/ui/commands/generic_chrome_command.h"
 
+@class ChromeIdentity;
+
 typedef void (^ShowSigninCommandCompletionCallback)(BOOL succeeded);
 
 enum AuthenticationOperation {
@@ -39,12 +41,13 @@ enum AuthenticationOperation {
 // Initializes a command to perform the specified operation with a
 // SigninInteractionController and invoke a possibly-nil callback when finished.
 - (instancetype)initWithOperation:(AuthenticationOperation)operation
+                         identity:(ChromeIdentity*)identity
                       accessPoint:(signin_metrics::AccessPoint)accessPoint
                       promoAction:(signin_metrics::PromoAction)promoAction
                          callback:(ShowSigninCommandCompletionCallback)callback
     NS_DESIGNATED_INITIALIZER;
 
-// Initializes a ShowSigninCommand with a nil callback.
+// Initializes a ShowSigninCommand with |identity| and |callback| set to nil.
 - (instancetype)initWithOperation:(AuthenticationOperation)operation
                       accessPoint:(signin_metrics::AccessPoint)accessPoint
                       promoAction:(signin_metrics::PromoAction)promoAction;
@@ -56,6 +59,11 @@ enum AuthenticationOperation {
 // The operation to perform during the sign-in flow.
 @property(nonatomic, readonly) AuthenticationOperation operation;
 
+// Chrome identity used to sign-in when the operation is
+// AUTHENTICATION_OPERATION_SIGNIN_PROMO_CONTINUE_AS (|identity should not be
+// nil). For other operation, |identity| should be nil.
+@property(nonatomic, readonly) ChromeIdentity* identity;
+
 // The access point of this authentication operation.
 @property(nonatomic, readonly) signin_metrics::AccessPoint accessPoint;