[ios] Update cred ext account verification api

New simpler two-step api.

Bug: 1049638
Change-Id: I8490144f181e140a909d3a740be9035ef0be1465
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2095056
Commit-Queue: David Jean <djean@chromium.org>
Reviewed-by: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Reviewed-by: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#750527}

ios/chrome/credential_provider_extension/account_verification_provider.h

@@ -11,12 +11,18 @@
 // as @optional, until implemented in all replacement providers.
 @protocol AccountVerificationProvider
 
-// Checks if the given |accountID| is valid, in the sense of
-// credential provider extension should provide or ignore credentials
-// associated with this account.  Completes with YES if account is valid or
+// Completes with a validationID (or nil) that can be used with
+// |validateValidationID:completionHandler:| at a later time.
+- (void)validationIDForAccountID:(NSString*)accountID
+               completionHandler:
+                   (void (^)(NSString*, NSError*))completionHandler;
+
+// Checks if the given |validationID| is valid, in the sense of
+// credential provider extension should provide or ignore/delete credentials
+// associated with this ID.  Completes with YES if account is valid or
 // NO with or without error if it is not.
-- (void)isValidProviderAccountID:(NSString*)accountID
-               completionHandler:(void (^)(BOOL, NSError*))completionHandler;
+- (void)validateValidationID:(NSString*)validationID
+           completionHandler:(void (^)(BOOL, NSError*))completionHandler;
 
 @end
 

ios/chrome/credential_provider_extension/account_verification_provider.mm

@@ -10,9 +10,18 @@
 
 @implementation AccountVerificationProvider
 
-- (void)isValidProviderAccountID:(NSString*)accountID
-               completionHandler:(void (^)(BOOL, NSError*))completionHandler {
-  // Default implementation return always true.
+- (void)validationIDForAccountID:(NSString*)accountID
+               completionHandler:
+                   (void (^)(NSString*, NSError*))completionHandler {
+  // Default implementation always return nil.
+  dispatch_async(dispatch_get_main_queue(), ^{
+    completionHandler(nil, nil);
+  });
+}
+
+- (void)validateValidationID:(NSString*)validationID
+           completionHandler:(void (^)(BOOL, NSError*))completionHandler {
+  // Default implementation always return true.
   dispatch_async(dispatch_get_main_queue(), ^{
     completionHandler(YES, nil);
   });