[iOS] Upstream chrome commands

ios/chrome/browser/ui/commands/UIKit+ChromeExecuteCommand.mm

+// Copyright 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import "ios/chrome/browser/ui/commands/UIKit+ChromeExecuteCommand.h"
+
+@implementation UIResponder (ChromeExecuteCommand)
+
+- (void)chromeExecuteCommand:(id)sender {
+  [[self nextResponder] chromeExecuteCommand:sender];
+}
+
+@end
+
+@implementation UIWindow (ChromeExecuteCommand)
+
+- (void)chromeExecuteCommand:(id)sender {
+  id delegate = [[UIApplication sharedApplication] delegate];
+
+  if ([delegate respondsToSelector:@selector(chromeExecuteCommand:)])
+    [delegate chromeExecuteCommand:sender];
+}
+
+@end