Remove ChromeBrowserProvider::IsOffTheRecordSessionActive().

ios/public/provider/chrome/browser/chrome_browser_provider.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.
 
 #include "ios/public/provider/chrome/browser/chrome_browser_provider.h"
 
 #include <cstddef>
 
 #include "base/logging.h"
 #include "components/metrics/metrics_provider.h"
@@ skipping 48 matching lines @@
 }
 
 std::string ChromeBrowserProvider::GetDistributionBrandCode() {
   return std::string();
 }
 
 std::string ChromeBrowserProvider::GetRiskData() {
   return std::string();
 }
 
-bool ChromeBrowserProvider::IsOffTheRecordSessionActive() {
-  return false;
-}
-
 void ChromeBrowserProvider::GetFaviconForURL(
     ios::ChromeBrowserState* browser_state,
     const GURL& page_url,
     const std::vector<int>& desired_sizes_in_pixel,
     const favicon_base::FaviconResultsCallback& callback) const {}
 
 UITextField<TextFieldStyling>* ChromeBrowserProvider::CreateStyledTextField(
     CGRect frame) const {
   return nil;
 }
@@ skipping 52 matching lines @@
 id<NativeAppWhitelistManager>
 ChromeBrowserProvider::GetNativeAppWhitelistManager() const {
   return nil;
 }
 
 void ChromeBrowserProvider::HideModalViewStack() const {}
 
 void ChromeBrowserProvider::LogIfModalViewsArePresented() const {}
 
 }  // namespace ios