Remove ChromeBrowserProvider::GetLiveTabContextProvider() method.

ios/public/provider/chrome/browser/sessions/test_live_tab_context_provider.cc

Index: ios/public/provider/chrome/browser/sessions/test_live_tab_context_provider.cc
diff --git a/ios/public/provider/chrome/browser/sessions/test_live_tab_context_provider.cc b/ios/public/provider/chrome/browser/sessions/test_live_tab_context_provider.cc
deleted file mode 100644
index 8a2a4aa86aa26d7392cc36d35528b39ec42b8da6..0000000000000000000000000000000000000000
--- a/ios/public/provider/chrome/browser/sessions/test_live_tab_context_provider.cc
+++ /dev/null
@@ -1,20 +0,0 @@
-// 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.
-
-#include "ios/public/provider/chrome/browser/sessions/test_live_tab_context_provider.h"
-
-sessions::LiveTabContext* TestLiveTabContextProvider::Create(
-    ios::ChromeBrowserState* browser_state) {
-  return nullptr;
-}
-
-sessions::LiveTabContext* TestLiveTabContextProvider::FindContextWithID(
-    int32_t desired_id) {
-  return nullptr;
-}
-
-sessions::LiveTabContext* TestLiveTabContextProvider::FindContextForTab(
-    const sessions::LiveTab* tab) {
-  return nullptr;
-}