[clean] Use CommandDispatcher to show/close Settings.

ios/shared/chrome/browser/ui/commands/command_dispatcher.mm

Index: ios/shared/chrome/browser/ui/commands/command_dispatcher.mm
diff --git a/ios/shared/chrome/browser/ui/commands/command_dispatcher.mm b/ios/shared/chrome/browser/ui/commands/command_dispatcher.mm
index 4829b3be6edab567d6bf400b4d5cd674c981149c..a3c12f8e54835ddbcb1a41b0c2e503e6d0772809 100644
--- a/ios/shared/chrome/browser/ui/commands/command_dispatcher.mm
+++ b/ios/shared/chrome/browser/ui/commands/command_dispatcher.mm
@@ -25,6 +25,10 @@
   _forwardingTargets[selector] = target;
 }
 
+- (void)stopDispatchingForSelector:(SEL)selector {
+  _forwardingTargets.erase(selector);
+}
+
 // |-stopDispatchingToTarget| should be called much less often than
 // |-forwardingTargetForSelector|, so removal is intentionally O(n) in order
 // to prioritize the speed of lookups.
@@ -37,7 +41,7 @@
   }
 
   for (auto* selector : selectorsToErase) {
-    _forwardingTargets.erase(selector);
+    [self stopDispatchingForSelector:selector];
   }
 }