Introduce TabRestoreServiceClient and //chrome implementation.

components/sessions/BUILD.gn

 # Copyright 2014 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.
 
 if (is_android) {
   import("//build/config/android/config.gni")
 }
 
 config("implementation") {
   defines = [ "SESSIONS_IMPLEMENTATION" ]
@@ skipping 50 matching lines @@
 source_set("shared") {
   visibility = [ ":*" ]
 
   sources = [
     "base_session_service.cc",
     "base_session_service.h",
     "base_session_service_commands.cc",
     "base_session_service_commands.h",
     "base_session_service_delegate.h",
     "core/serialized_navigation_driver.h",
+    "core/session_constants.cc",
+    "core/session_constants.h",
+    "core/tab_restore_service_client.h",
     "serialized_navigation_entry.cc",
     "serialized_navigation_entry.h",
     "session_backend.cc",
     "session_backend.h",
     "session_command.cc",
     "session_command.h",
     "session_id.cc",
     "session_id.h",
     "session_service_commands.cc",
     "session_service_commands.h",
@@ skipping 53 matching lines @@
     ]
     deps = [
       ":sessions",
       ":test_support",
       "//base/test:test_support",
       "//testing/gtest",
       "//third_party/protobuf:protobuf_lite",
     ]
   }
 }