Add ContextMenuCoordinator.

ios/chrome/browser/ui/context_menu/context_menu_wrangler_unittest.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/context_menu/context_menu_wrangler.h"
+
+#import <UIKit/UIKit.h>
+
+#include "base/mac/scoped_nsobject.h"
+#import "ios/web/public/web_state/context_menu_params.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/platform_test.h"
+
+namespace {

[Eugene But (OOO till 7-30), 2016/05/12 22:27:49]

NIT: No need to put tests into anonymous namespace 

[michaeldo, 2016/05/12 23:32:43]

Done.

+
+class ContextMenuWranglerTest : public PlatformTest {

[Eugene But (OOO till 7-30), 2016/05/12 22:27:49]

Needs comment

[michaeldo, 2016/05/12 23:32:43]

Done.

+ public:
+  ContextMenuWranglerTest() {
+    _window.reset(
+        [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]);
+    [_window makeKeyAndVisible];
+  }
+
+ protected:
+  base::scoped_nsobject<ContextMenuWrangler> _menuWrangler;
+  base::scoped_nsobject<UIWindow> _window;
+};
+
+TEST_F(ContextMenuWranglerTest, DisplayContextMenu) {

[Eugene But (OOO till 7-30), 2016/05/12 22:27:49]

Every test needs comments

[michaeldo, 2016/05/12 23:32:43]

Done.

+  web::ContextMenuParams params;
+  params.location = CGPointZero;
+  params.view.reset([_window retain]);
+  _menuWrangler.reset(
+      [[ContextMenuWrangler alloc] initWithContextMenuParams:params]);
+
+  [_menuWrangler appendItemWithTitle:@"foo" action:NULL];

[Eugene But (OOO till 7-30), 2016/05/12 22:27:49]

s/NULL/nil or nullptr

[michaeldo, 2016/05/12 23:32:43]

Done.

+  [_menuWrangler appendItemWithTitle:@"bar"
+                              action:^{
+                              }];
+
+  [_menuWrangler present];
+
+  EXPECT_TRUE([_menuWrangler isVisible]);
+}
+
+}  // namespace