[iOS] Refactoring web CRWSessionController user agent code.

ios/web/web_state/ui/crw_web_controller.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/web/web_state/ui/crw_web_controller.h"
 
 #import <WebKit/WebKit.h>
 
 #import <objc/runtime.h>
 #include <stddef.h>
@@ skipping 1551 matching lines @@
   _loadPhase = web::LOAD_REQUESTED;
   _lastRegisteredRequestURL = requestURL;
 
   if (!(transition & ui::PAGE_TRANSITION_IS_REDIRECT_MASK)) {
     // Record state of outgoing page.
     [self recordStateInHistory];
   }
 
   [_delegate webWillAddPendingURL:requestURL transition:transition];
   // Add or update pending url.
   if (_webStateImpl->GetNavigationManagerImpl().GetPendingItem()) {

[Eugene But (OOO till 7-30), 2017/02/16 02:20:48]

nit: Do you want to create a local variable for NavigationManagerImpl?

[liaoyuke, 2017/02/16 22:04:29]

Acknowledged.

     // Update the existing pending entry.
     // Typically on PAGE_TRANSITION_CLIENT_REDIRECT.
     [[self sessionController] updatePendingItem:requestURL];
   } else {
     // A new session history entry needs to be created.
-    [[self sessionController] addPendingItem:requestURL
-                                    referrer:referrer
-                                  transition:transition
-                           rendererInitiated:YES];
+    _webStateImpl->GetNavigationManagerImpl().AddRendererInitiatedPendingItem(
+        requestURL, referrer, transition);
   }
   _webStateImpl->SetIsLoading(true);
   _webStateImpl->OnProvisionalNavigationStarted(requestURL);
 }
 
 - (void)updateHTML5HistoryState {
   web::NavigationItemImpl* currentItem =
       static_cast<web::NavigationItemImpl*>([self currentNavItem]);
   if (!currentItem)
     return;
@@ skipping 313 matching lines @@
   } else {
     // Clear transient view before making any changes to history and navigation
     // manager. TODO(stuartmorgan): Drive Transient Item clearing from
     // navigation system, rather than from WebController.
     [self clearTransientContentView];
 
     // TODO(stuartmorgan): Why doesn't recordStateInHistory get called for
     // forward/back transitions?
     [self recordStateInHistory];
 
-    CRWSessionController* history =
-        _webStateImpl->GetNavigationManagerImpl().GetSessionController();
     if (!self.currentSessionEntry)
       initialNavigation = YES;
-    [history addPendingItem:navUrl
-                   referrer:params.referrer
-                 transition:transition
-          rendererInitiated:params.is_renderer_initiated];
+
+    if (params.is_renderer_initiated) {
+      _webStateImpl->GetNavigationManagerImpl().AddRendererInitiatedPendingItem(

[Eugene But (OOO till 7-30), 2017/02/16 02:20:48]

Having 2 APIs for adding pendingItem looks error prone. How about creating a
enum inside navigation_manager_impl.h?:

class enum PendingItemType {
  USER_INITIATED = 1,
  RENDERER_INITIATED = 1,
};

[liaoyuke, 2017/02/16 22:04:29]

I like this idea, but I changed the class name to ItemInitiationType, which I
think is more informative. Please let me know if you don't like it.

[Eugene But (OOO till 7-30), 2017/02/17 00:00:23]

How about NavigationInitiationType ?

[Eugene But (OOO till 7-30), 2017/02/17 01:21:11]

Please address this comment.

[liaoyuke, 2017/02/17 01:58:45]

Agreed, NavigationInitiationType is more informative than ItemInitiationType.

+          navUrl, params.referrer, transition);
+    } else {
+      _webStateImpl->GetNavigationManagerImpl().AddUserInitiatedPendingItem(
+          navUrl, params.referrer, transition);
+    }
+
     web::NavigationItemImpl* addedItem =
         [self currentSessionEntry].navigationItemImpl;
     DCHECK(addedItem);
     if (params.extra_headers)
       addedItem->AddHttpRequestHeaders(params.extra_headers);
     if (params.post_data) {
       DCHECK([addedItem->GetHttpRequestHeaders() objectForKey:@"Content-Type"])
           << "Post data should have an associated content type";
       addedItem->SetPostData(params.post_data);
       addedItem->SetShouldSkipRepostFormConfirmation(true);
@@ skipping 3382 matching lines @@
 - (void)simulateLoadRequestWithURL:(const GURL&)URL {
   _lastRegisteredRequestURL = URL;
   _loadPhase = web::LOAD_REQUESTED;
 }
 
 - (NSString*)refererFromNavigationAction:(WKNavigationAction*)action {
   return [action.request valueForHTTPHeaderField:@"Referer"];
 }
 
 @end