Remove ChromeBrowserProvider::GetLiveTabContextProvider() method.

ios/chrome/browser/sessions/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.
 
 source_set("sessions") {
   configs += [ "//build/config/compiler:enable_arc" ]
   sources = [
     "ios_chrome_session_tab_helper.h",
     "ios_chrome_session_tab_helper.mm",
     "ios_chrome_tab_restore_service_client.h",
     "ios_chrome_tab_restore_service_client.mm",
     "ios_chrome_tab_restore_service_factory.cc",
     "ios_chrome_tab_restore_service_factory.h",
   ]
   deps = [
     "//base",
     "//components/keyed_service/ios",
     "//components/sessions",
     "//ios/chrome/browser",
     "//ios/chrome/browser/browser_state",
+    "//ios/chrome/browser/tabs",
+    "//ios/chrome/browser/ui:browser_list",
     "//ios/public/provider/chrome/browser",
-    "//ios/public/provider/chrome/browser/sessions",
     "//ios/web",
     "//url",
   ]
+  public_deps = [
+    ":sessions_non_arc",
+  ]
 }
 
-source_set("sessions_internal") {
+source_set("sessions_non_arc") {
+  visibility = [ ":sessions" ]
   sources = [
     "NSCoder+Compatibility.h",
     "NSCoder+Compatibility.mm",
     "session_service.h",
     "session_service.mm",
     "session_util.h",
     "session_util.mm",
     "session_window.h",
     "session_window.mm",
     "tab_restore_service_delegate_impl_ios.h",
     "tab_restore_service_delegate_impl_ios.mm",
     "tab_restore_service_delegate_impl_ios_factory.h",
     "tab_restore_service_delegate_impl_ios_factory.mm",
-    "tab_restore_service_delegate_provider_impl.h",
-    "tab_restore_service_delegate_provider_impl.mm",
   ]
   deps = [
     "//base",
     "//components/keyed_service/core",
     "//components/keyed_service/ios",
     "//components/sessions",
     "//ios/chrome/browser/browser_state",
     "//ios/chrome/browser/tabs",
     "//ios/chrome/browser/ui:browser_list",
-    "//ios/public/provider/chrome/browser/sessions",
     "//ios/web",
     "//net",
   ]
   libs = [ "UIKit.framework" ]
 }
 
 source_set("test_support") {
   testonly = true
   sources = [
     "test_session_service.h",
     "test_session_service.mm",
   ]
   deps = [
-    ":sessions_internal",
+    ":sessions",
   ]
 }
 
 source_set("unit_tests") {
   testonly = true
   sources = [
     "session_service_unittest.mm",
     "session_window_unittest.mm",
   ]
   deps = [
     ":resources_unit_tests",
-    ":sessions_internal",
+    ":sessions",
     "//base",
     "//ios/chrome/browser",
     "//ios/chrome/browser/browser_state:test_support",
     "//ios/web",
     "//ios/web:test_support",
     "//testing/gtest",
     "//third_party/ocmock",
   ]
 }
 
 bundle_data("resources_unit_tests") {
   visibility = [ ":unit_tests" ]
   testonly = true
   sources = [
     "//ios/chrome/test/data/sessions/corrupted.plist",
   ]
   outputs = [
     "{{bundle_resources_dir}}/ios/chrome/test/data/sessions/{{source_file_part}}",
   ]
 }