[Navigation Experiment] Add WKBasedNavigationManagerImpl.

ios/web/navigation/navigation_manager_impl.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/web/navigation/navigation_manager_impl.h"
+
+#include "ui/base/page_transition_types.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+namespace web {
+
+NavigationManager::WebLoadParams::WebLoadParams(const GURL& url)
+    : url(url),
+      transition_type(ui::PAGE_TRANSITION_LINK),
+      user_agent_override_option(UserAgentOverrideOption::INHERIT),
+      is_renderer_initiated(false),
+      post_data(nil) {}
+
+NavigationManager::WebLoadParams::~WebLoadParams() {}
+
+NavigationManager::WebLoadParams::WebLoadParams(const WebLoadParams& other)
+    : url(other.url),
+      referrer(other.referrer),
+      transition_type(other.transition_type),
+      user_agent_override_option(other.user_agent_override_option),
+      is_renderer_initiated(other.is_renderer_initiated),
+      extra_headers([other.extra_headers copy]),
+      post_data([other.post_data copy]) {}
+
+NavigationManager::WebLoadParams& NavigationManager::WebLoadParams::operator=(
+    const WebLoadParams& other) {
+  url = other.url;
+  referrer = other.referrer;
+  is_renderer_initiated = other.is_renderer_initiated;
+  transition_type = other.transition_type;
+  user_agent_override_option = other.user_agent_override_option;
+  extra_headers.reset([other.extra_headers copy]);
+  post_data.reset([other.post_data copy]);
+
+  return *this;
+}
+
+}  // namespace web