Remove ChromeBrowserProvider::GetLiveTabContextProvider() method.

ios/public/provider/chrome/browser/sessions/BUILD.gn

Index: ios/public/provider/chrome/browser/sessions/BUILD.gn
diff --git a/ios/public/provider/chrome/browser/sessions/BUILD.gn b/ios/public/provider/chrome/browser/sessions/BUILD.gn
index f9d0f6f979321bdcf0d47b6051461429dbf13bbc..6d75d90c9f7e1449d610d86795d515848d8ec301 100644
--- a/ios/public/provider/chrome/browser/sessions/BUILD.gn
+++ b/ios/public/provider/chrome/browser/sessions/BUILD.gn
@@ -2,23 +2,14 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("sessions") {
-  sources = [
-    "live_tab_context_provider.h",
-  ]
-}
-
 source_set("test_support") {
   testonly = true
   sources = [
-    "test_live_tab_context_provider.cc",
-    "test_live_tab_context_provider.h",
     "test_synced_window_delegates_getter.cc",
     "test_synced_window_delegates_getter.h",
   ]
   deps = [
     "//base",
     "//components/sync_sessions",
-    "//ios/public/provider/chrome/browser/sessions",
   ]
 }