Mac: Make ScopedTypeRef require explicit constructors

ios/web/web_state/web_state_delegate_bridge_unittest.mm

 // Copyright 2016 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/web/public/web_state/web_state_delegate_bridge.h"
 
 #include <memory>
 
 #import "base/mac/scoped_nsobject.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 35 matching lines @@
 }
 
 // Tests |HandleContextMenu| forwarding.
 TEST_F(WebStateDelegateBridgeTest, HandleContextMenu) {
   EXPECT_EQ(nil, [delegate_ contextMenuParams]);
   web::ContextMenuParams context_menu_params;
   context_menu_params.menu_title.reset([@"Menu title" copy]);
   context_menu_params.link_url = GURL("http://www.url.com");
   context_menu_params.src_url = GURL("http://www.url.com/image.jpeg");
   context_menu_params.referrer_policy = web::ReferrerPolicyOrigin;
-  context_menu_params.view = [UIView new];
+  context_menu_params.view.reset([UIView new]);

[Eugene But (OOO till 7-30), 2016/06/01 05:12:07]

Optional NIT: Since you touching this, could you please s/[UIView new]/[[UIView
alloc] init]

https://google.github.io/styleguide/objcguide.xml#Avoid_+new

   context_menu_params.location = CGPointMake(5.0, 5.0);
   bridge_->HandleContextMenu(nullptr, context_menu_params);
   web::ContextMenuParams* result_params = [delegate_ contextMenuParams];
   EXPECT_NE(nullptr, result_params);
   EXPECT_EQ(context_menu_params.menu_title, result_params->menu_title);
   EXPECT_EQ(context_menu_params.link_url, result_params->link_url);
   EXPECT_EQ(context_menu_params.src_url, result_params->src_url);
   EXPECT_EQ(context_menu_params.referrer_policy,
             result_params->referrer_policy);
   EXPECT_EQ(context_menu_params.view, result_params->view);
   EXPECT_EQ(context_menu_params.location.x, result_params->location.x);
   EXPECT_EQ(context_menu_params.location.y, result_params->location.y);
 }
 
 }  // namespace web