Remove ChromeBrowserProvider::IsOffTheRecordSessionActive().

ios/chrome/browser/ui/BUILD.gn

 # Copyright 2016 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("//build/config/ios/rules.gni")
 
 source_set("ui_arc") {
   sources = [
     "network_activity_indicator_manager.h",
     "network_activity_indicator_manager.mm",
   ]
   deps = [
     "//base",
   ]
   configs += [ "//build/config/compiler:enable_arc" ]
 }
 
 source_set("ui") {
   configs += [ "//build/config/compiler:enable_arc" ]
   sources = [
     "UIView+SizeClassSupport.h",
     "UIView+SizeClassSupport.mm",
     "animation_util.h",
     "animation_util.mm",
     "background_generator.h",
     "background_generator.mm",
-    "browser_otr_state.h",
-    "browser_otr_state.mm",
     "favicon_view.h",
     "favicon_view.mm",
     "file_locations.h",
     "file_locations.mm",
     "image_util.h",
     "image_util.mm",
     "native_content_controller.h",
     "native_content_controller.mm",
     "orientation_limiting_navigation_controller.h",
     "orientation_limiting_navigation_controller.mm",
@@ skipping 13 matching lines @@
     "uikit_ui_util.h",
     "uikit_ui_util.mm",
     "url_loader.h",
   ]
   deps = [
     "//base",
     "//base:i18n",
     "//ios/chrome/browser",
     "//ios/chrome/browser/favicon",
     "//ios/chrome/browser/ui/commands",
-    "//ios/public/provider/chrome/browser",
     "//ios/web",
     "//ui/base",
     "//ui/gfx",
   ]
   public_deps = [
     ":ui_arc",
   ]
   allow_circular_includes_from = [
     ":ui_arc",
     "//ios/chrome/browser/ui/commands",
@@ skipping 385 matching lines @@
 }
 
 # Clean skeleton targets
 source_set("ui_clean_skeleton") {
   sources = [
     "ui_types.h",
   ]
 
   configs += [ "//build/config/compiler:enable_arc" ]
 }