Introduce a layering in the invalidation component as public and impl

sync/tools/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.
 
 import("//testing/test.gni")
 
 if (is_linux && !is_chromeos) {
   # TODO(GYP): Figure out which of these work and are needed on other platforms.
   source_set("common") {
     testonly = true
 
     sources = [
       "invalidation_helper.cc",
       "invalidation_helper.h",
       "null_invalidation_state_tracker.cc",
       "null_invalidation_state_tracker.h",
     ]
 
     deps = [
       "//base",
-      "//components/invalidation",
+      "//components/invalidation/impl",
       "//sync",
     ]
   }
 
   test("sync_listen_notifications") {
     sources = [
       "sync_listen_notifications.cc",
     ]
 
     defines = [ "SYNC_TEST" ]
 
     deps = [
       ":common",
       "//base",
-      "//components/invalidation",
+      "//components/invalidation/impl",
       "//jingle:notifier",
       "//net",
       "//net:test_support",
       "//sync",
       "//sync:test_support_sync_core",
     ]
   }
 
   test("sync_client") {
     sources = [
       "sync_client.cc",
     ]
 
     defines = [ "SYNC_TEST" ]
 
     deps = [
       ":common",
       "//base",
-      "//components/invalidation",
+      "//components/invalidation/impl",
       "//jingle:notifier",
       "//net",
       "//net:test_support",
       "//sync",
       "//sync:test_support_sync_core",
     ]
   }
 }