[iOS] Refactoring web CRWSessionController user agent code.

ios/web/navigation/navigation_manager_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/navigation/navigation_manager_impl.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 50 matching lines @@
   referrer = other.referrer;
   is_renderer_initiated = other.is_renderer_initiated;
   transition_type = other.transition_type;
   extra_headers.reset([other.extra_headers copy]);
   post_data.reset([other.post_data copy]);
 
   return *this;
 }
 
 NavigationManagerImpl::NavigationManagerImpl()
-    : delegate_(nullptr), browser_state_(nullptr), facade_delegate_(nullptr) {}
+    : override_desktop_user_agent_for_next_pending_item_(false),
+      delegate_(nullptr),
+      browser_state_(nullptr),
+      facade_delegate_(nullptr) {}
 
 NavigationManagerImpl::~NavigationManagerImpl() {
   // The facade layer should be deleted before this object.
   DCHECK(!facade_delegate_);
 
   [session_controller_ setNavigationManager:nullptr];
 }
 
 void NavigationManagerImpl::SetDelegate(NavigationManagerDelegate* delegate) {
   delegate_ = delegate;
@@ skipping 84 matching lines @@
 }
 
 void NavigationManagerImpl::LoadURL(const GURL& url,
                                     const web::Referrer& referrer,
                                     ui::PageTransition type) {
   WebState::OpenURLParams params(url, referrer,
                                  WindowOpenDisposition::CURRENT_TAB, type, NO);
   delegate_->GetWebState()->OpenURL(params);
 }
 
+void NavigationManagerImpl::AddPendingItem(
+    const GURL& url,
+    const web::Referrer& referrer,
+    ui::PageTransition navigation_type,
+    NavigationInitiationType initiation_type) {
+  [session_controller_ addPendingItem:url
+                             referrer:referrer
+                           transition:navigation_type
+                       initiationType:initiation_type];
+
+  // Do nothing if pending item is the same as last committed item.
+  if (GetPendingItem()) {
+    bool use_desktop_user_agent =
+        override_desktop_user_agent_for_next_pending_item_ ||
+        (GetLastCommittedItem() &&
+         GetLastCommittedItem()->IsOverridingUserAgent());
+    GetPendingItem()->SetIsOverridingUserAgent(use_desktop_user_agent);
+    override_desktop_user_agent_for_next_pending_item_ = false;
+  }
+}
+
 NavigationItem* NavigationManagerImpl::GetLastUserItem() const {
   CRWSessionEntry* entry = [session_controller_ lastUserEntry];
   return [entry navigationItem];
 }
 
 NavigationItem* NavigationManagerImpl::GetPreviousItem() const {
   CRWSessionEntry* entry = [session_controller_ previousEntry];
   return [entry navigationItem];
 }
 
@@ skipping 203 matching lines @@
     // Result may be out of bounds, so stop trying to skip redirect items and
     // simply add the remainder.
     result += offset;
     if (result < 0 /* overflow */)
       result = INT_MAX;
   }
 
   return result;
 }
 
+void NavigationManagerImpl::OverrideDesktopUserAgentForNextPendingItem() {
+  if (GetPendingItem())
+    GetPendingItem()->SetIsOverridingUserAgent(true);
+  else
+    override_desktop_user_agent_for_next_pending_item_ = true;
+}
+
 bool NavigationManagerImpl::IsRedirectItemAtIndex(int index) const {
   DCHECK_GT(index, 0);
   DCHECK_LT(index, GetItemCount());
   ui::PageTransition transition = GetItemAtIndex(index)->GetTransitionType();
   return transition & ui::PAGE_TRANSITION_IS_REDIRECT_MASK;
 }
 
 }  // namespace web