Reland of (Set)IsOverridingUserAgent should be called on VisibleItem

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 1051 matching lines @@
 
   return [tab canSwitchToReaderMode];
 }
 
 - (BOOL)canUseDesktopUserAgent {
   Tab* tab = [_model currentTab];
   if ([self isTabNativePage:tab])
     return NO;
 
   // If |useDesktopUserAgent| is |NO|, allow useDesktopUserAgent.
-  return !tab.useDesktopUserAgent;
+  return !tab.usesDesktopUserAgent;
 }
 
 // Whether the sharing menu should be shown.
 - (BOOL)canShowShareMenu {
   Tab* tab = [_model currentTab];
   // TODO(shreyasv): Make it so the URL returned by the tab is always valid and
   // remove check on net::NSURLWithGURL(tab.url) ( http://crbug.com/400999 ).
   return tab && !tab.url.SchemeIs(kChromeUIScheme) &&
          net::NSURLWithGURL(tab.url);
 }
@@ skipping 3724 matching lines @@
     if ((seenToolbar && !seenInfoBarContainer) ||
         (seenInfoBarContainer && !seenContentArea))
       return NO;
   }
   return YES;
 }
 
 #pragma mark - PreloadControllerDelegate methods
 
 - (BOOL)shouldUseDesktopUserAgent {
-  return [_model currentTab].useDesktopUserAgent;
+  return [_model currentTab].usesDesktopUserAgent;
 }
 
 - (CRWSessionEntry*)currentSessionEntry {
   Tab* tab = [_model currentTab];
   if (![tab navigationManager])
     return nil;
   return [[tab navigationManager]->GetSessionController() currentEntry];
 }
 
 #pragma mark - BookmarkBridgeMethods
@@ skipping 197 matching lines @@
 
 - (UIView*)voiceSearchButton {
   return _voiceSearchButton;
 }
 
 - (id<LogoAnimationControllerOwner>)logoAnimationControllerOwner {
   return [self currentLogoAnimationControllerOwner];
 }
 
 @end