[iOS] Upstream web_controller_provider_impl.{h,mm}.

ios/chrome/browser/web/web_controller_provider_factory_impl.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/chrome/browser/web/web_controller_provider_factory_impl.h"
+
+#include "base/memory/ptr_util.h"
+#import "ios/chrome/browser/web/web_controller_provider_impl.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+WebControllerProviderFactoryImpl::WebControllerProviderFactoryImpl() {}
+
+WebControllerProviderFactoryImpl::~WebControllerProviderFactoryImpl() {}
+
+std::unique_ptr<ios::WebControllerProvider>
+WebControllerProviderFactoryImpl::CreateWebControllerProvider(
+    web::BrowserState* browser_state) {
+  return base::MakeUnique<WebControllerProviderImpl>(browser_state);
+}