Enable iOS Password AutoFill on the legacy login form (#6)

Set textContentType (username / password) on the xAuth login fields so iOS
recognises the form and offers saved logins and the Passwords key in the
QuickType bar — the native equivalent of tagging a web form's inputs with
autocomplete=username / current-password.

Author: gingerbeardman

LegacyLogin/BHTLegacyLoginViewController.m

@@ -235,8 +235,13 @@ - (void)viewDidLoad {
 
     self.userField = [self field:@"Username, email or phone" secure:NO];
     self.userField.keyboardType = UIKeyboardTypeEmailAddress;
+    // Tag the fields so iOS Password AutoFill recognises the form and offers
+    // saved logins / the Passwords key in the QuickType bar (the native
+    // equivalent of autocomplete=username / current-password on a web form).
+    self.userField.textContentType = UITextContentTypeUsername;
 
     self.passField = [self field:@"Password" secure:YES];
+    self.passField.textContentType = UITextContentTypePassword;
 
     self.actionButton = [UIButton buttonWithType:UIButtonTypeSystem];
     [self.actionButton setTitle:@"Log in" forState:UIControlStateNormal];