[iOS Clean] Update ContextMenuItem to use a single command.

ios/clean/chrome/browser/ui/context_menu/context_menu_view_controller.mm

 // Copyright 2017 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/clean/chrome/browser/ui/context_menu/context_menu_view_controller.h"
 
 #include "base/logging.h"
+#import "ios/clean/chrome/browser/ui/commands/context_menu_commands.h"
 #import "ios/clean/chrome/browser/ui/context_menu/context_menu_context.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 namespace {
 // Typedef the block parameter for UIAlertAction for readability.
 typedef void (^AlertActionHandler)(UIAlertAction*);
-// Sends |commands| to |dispatcher| using |context| as the menu context.
-void DispatchContextMenuCommands(const std::vector<SEL>& commands,
-                                 id dispatcher,
-                                 ContextMenuContext* context) {
-  DCHECK(dispatcher);
-  DCHECK(context);
-// |-performSelector:withObject:| throws a warning in ARC because the compiler
-// doesn't know how to handle the memory management of the returned values.
-// Since all ContextMenuCommands return void, these warning can be ignored
-// here.
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
-  for (SEL command : commands) {
-    [dispatcher performSelector:command withObject:context];
-  }
-#pragma clang diagnostic pop
-}
 }
 
 @interface ContextMenuViewController ()
 // The dispatcher passed on initialization.
 @property(nonatomic, readonly, weak) id<ContextMenuCommands> dispatcher;
 // The context passed on initialization.
 @property(nonatomic, strong) ContextMenuContext* context;
 
 // Creates an UIAlertAction for |item| using |style| to manage the action's
 // appearance.
@@ skipping 40 matching lines @@
                                      style:UIAlertActionStyleCancel]];
 }
 
 #pragma mark -
 
 - (UIAlertAction*)alertActionForItem:(ContextMenuItem*)item
                                style:(UIAlertActionStyle)style {
   DCHECK(item);
   // Create a block that dispatches |item|'s ContextMenuCommands.
   AlertActionHandler handler = ^(UIAlertAction* action) {
-    DispatchContextMenuCommands(item.commands, self.dispatcher, self.context);
+// |-performSelector:withObject:| throws a warning in ARC because the compiler
+// doesn't know how to handle the memory management of the returned values.
+// Since all ContextMenuCommands return void, these warning can be ignored
+// here.
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
+    // TODO: Convert to DCHECK once all commands are implemented.
+    if (item.command)
+      [self.dispatcher performSelector:item.command withObject:self.context];
+    // If the command opens a new tab, the context menu will be hidden
+    // automatically.  If not, dispatch |-hideMenuContext:| to stop the menu UI.
+    if (!item.commandOpensTab) {
+      [self.dispatcher performSelector:@selector(hideContextMenu:)
+                            withObject:self.context];
+    }
+#pragma clang diagnostic pop
   };
   return [UIAlertAction actionWithTitle:item.title style:style handler:handler];
 }
 
 @end