[Navigation Experiment] Add WKBasedNavigationManagerImpl.

ios/web/web_state/web_state_impl.mm

 // Copyright 2013 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/web_state/web_state_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/threading/sequenced_task_runner_handle.h"
 #import "ios/web/interstitials/web_interstitial_impl.h"
 #import "ios/web/navigation/crw_session_controller.h"
 #import "ios/web/navigation/legacy_navigation_manager_impl.h"
 #import "ios/web/navigation/navigation_item_impl.h"
 #import "ios/web/navigation/session_storage_builder.h"
+#import "ios/web/navigation/wk_based_navigation_manager_impl.h"
 #include "ios/web/public/browser_state.h"
 #import "ios/web/public/crw_session_storage.h"
 #import "ios/web/public/java_script_dialog_presenter.h"
 #import "ios/web/public/navigation_item.h"
 #include "ios/web/public/url_util.h"
 #import "ios/web/public/web_client.h"
 #import "ios/web/public/web_state/context_menu_params.h"
 #import "ios/web/public/web_state/ui/crw_content_view.h"
 #import "ios/web/public/web_state/web_state_delegate.h"
 #include "ios/web/public/web_state/web_state_interface_provider.h"
 #include "ios/web/public/web_state/web_state_observer.h"
 #import "ios/web/public/web_state/web_state_policy_decider.h"
 #include "ios/web/public/web_thread.h"
 #include "ios/web/public/webui/web_ui_ios_controller.h"
 #include "ios/web/web_state/global_web_state_event_tracker.h"
 #import "ios/web/web_state/navigation_context_impl.h"
 #import "ios/web/web_state/session_certificate_policy_cache_impl.h"
 #import "ios/web/web_state/ui/crw_web_controller.h"
 #import "ios/web/web_state/ui/crw_web_controller_container_view.h"
+#import "ios/web/web_state/ui/web_view_navigation_proxy.h"
+#import "ios/web/web_state/ui/web_view_navigation_proxy_impl.h"
 #include "ios/web/webui/web_ui_ios_controller_factory_registry.h"
 #include "ios/web/webui/web_ui_ios_impl.h"
 #include "net/http/http_response_headers.h"
 #include "ui/gfx/image/image.h"
 
 namespace web {
 
 /* static */
 std::unique_ptr<WebState> WebState::Create(const CreateParams& params) {
   std::unique_ptr<WebStateImpl> web_state(new WebStateImpl(params));
@@ skipping 28 matching lines @@
       web_controller_(nil),
       interstitial_(nullptr),
       created_with_opener_(params.created_with_opener),
       weak_factory_(this) {
   // Create or deserialize the NavigationManager.
   if (session_storage) {
     SessionStorageBuilder session_storage_builder;
     session_storage_builder.ExtractSessionState(this, session_storage);
   } else {
     navigation_manager_ = base::WrapUnique<NavigationManagerImpl>(
-        new LegacyNavigationManagerImpl);
+        web::GetWebClient()->IsSlimNavigationManagerEnabled()
+            ? (NavigationManagerImpl*)(new WKBasedNavigationManagerImpl)

[Eugene But (OOO till 7-30), 2017/06/29 01:48:19]

Please use C++ casting. But do you even need to cast here? Can you use
base::MakeUnique instead?

[danyao, 2017/06/29 16:05:26]

The cast is needed because I want to use the ? : shorthand, which requires the
two arms of : to return the same type.

MakeUnique doesn't work here because we want to selectively make one of the
derived classes. We would still need the conditional selection.

I changed this to a proper if statement to avoid the casting. It's just a little
bit longer. Also tweaked the contract of
SessionStorageBuilder::ExtractSessionState to require the navigation manager to
be already allocated in the passed-in WebStateImpl. This way we only need to do
this conditional instantiation of navigation manager once in this class.

+            : (NavigationManagerImpl*)(new LegacyNavigationManagerImpl));
     certificate_policy_cache_ =
         base::MakeUnique<SessionCertificatePolicyCacheImpl>();
   }
   navigation_manager_->SetDelegate(this);
   navigation_manager_->SetBrowserState(params.browser_state);
   // Send creation event and create the web controller.
   GlobalWebStateEventTracker::GetInstance()->OnWebStateCreated(this);
   web_controller_.reset([[CRWWebController alloc] initWithWebState:this]);
 }
 
@@ skipping 631 matching lines @@
 void WebStateImpl::OnNavigationItemCommitted(
     const LoadCommittedDetails& load_details) {
   for (auto& observer : observers_)
     observer.NavigationItemCommitted(load_details);
 }
 
 WebState* WebStateImpl::GetWebState() {
   return this;
 }
 
+WebViewNavigationProxy* WebStateImpl::GetWebViewNavigationProxy() const {
+  return [web_controller_ webViewNavigationProxy];
+}
+
 }  // namespace web