Set user agent type of transient item the same as pending item.

ios/chrome/browser/ui/browser_view_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/chrome/browser/ui/browser_view_controller.h"
 
 #import <AssetsLibrary/AssetsLibrary.h>
 #import <MobileCoreServices/MobileCoreServices.h>
 #import <PassKit/PassKit.h>
 #import <Photos/Photos.h>
@@ skipping 1077 matching lines @@
 
   auto* helper = FindTabHelper::FromWebState(tab.webState);
   return (helper && helper->CurrentPageSupportsFindInPage() &&
           !helper->IsFindUIActive());
 }
 
 - (web::UserAgentType)userAgentType {
   web::WebState* webState = [_model currentTab].webState;
   if (!webState)
     return web::UserAgentType::NONE;
-  web::NavigationItem* visibleItem =
-      webState->GetNavigationManager()->GetVisibleItem();
-  if (!visibleItem)
+
+  // TODO(crbug.com/707081): Clean this up once the bug is fixed.

[Eugene But (OOO till 7-30), 2017/03/31 18:06:40]

We should not land this code duplication, unless we have a short term plan to
fix this. crbug.com/707081 is about finding a replacement for currentItem, but
there will be no replacement. As it stands, crbug.com/707081 is WAI.

[liaoyuke, 2017/03/31 18:29:03]

Makes sense! I'll just keep this piece of code as visibleItem for now, it makes
a difference in some edge cases when there is a renderer-initiated pending item,
but I think both behaviors are fine, I made the change only for the sake of
consistency.

+  web::NavigationItem* item =
+      webState->GetNavigationManager()->GetTransientItem();
+  if (!item)
+    item = webState->GetNavigationManager()->GetPendingItem();
+  if (!item)
+    item = webState->GetNavigationManager()->GetLastCommittedItem();
+
+  if (!item)
     return web::UserAgentType::NONE;
 
-  return visibleItem->GetUserAgentType();
+  return item->GetUserAgentType();
 }
 
 - (void)setVisible:(BOOL)visible {
   if (_visible == visible)
     return;
   _visible = visible;
 }
 
 - (void)setViewVisible:(BOOL)viewVisible {
   if (_viewVisible == viewVisible)
@@ skipping 4012 matching lines @@
 
 - (UIView*)voiceSearchButton {
   return _voiceSearchButton;
 }
 
 - (id<LogoAnimationControllerOwner>)logoAnimationControllerOwner {
   return [self currentLogoAnimationControllerOwner];
 }
 
 @end