Introduce a layering in the invalidation component as public and impl

chrome/chrome_browser.gypi

 # Copyright 2012 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.
 
 {
   'variables': {
     # All .cc, .h, .m, and .mm files under browser except for:
     # * tests and mocks.
     # * code below browser/chromeos
     # * code below browser/extensions
@@ skipping 3132 matching lines @@
         '../components/components.gyp:enhanced_bookmarks',
         '../components/components.gyp:favicon_base',
         '../components/components.gyp:favicon_core',
         '../components/components.gyp:gcm_driver',
         '../components/components.gyp:google_core_browser',
         '../components/components.gyp:handoff',
         '../components/components.gyp:history_core_browser',
         '../components/components.gyp:history_core_common',
         '../components/components.gyp:infobars_core',
         '../components/components.gyp:instance_id',
-        '../components/components.gyp:invalidation',
+        '../components/components.gyp:invalidation_impl',
         '../components/components.gyp:metrics',
         '../components/components.gyp:metrics_gpu',
         '../components/components.gyp:metrics_net',
         '../components/components.gyp:metrics_profiler',
         '../components/components.gyp:navigation_metrics',
         '../components/components.gyp:network_time',
         '../components/components.gyp:offline_pages',
         '../components/components.gyp:omnibox',
         '../components/components.gyp:os_crypt',
         '../components/components.gyp:password_manager_core_browser',
@@ skipping 890 matching lines @@
           'variables': {
             'proto_in_dir': 'browser/sync_file_system/drive_backend',
             'proto_out_dir': 'chrome/browser/sync_file_system/drive_backend',
           },
           'includes': [ '../build/protoc.gypi' ]
         },
       ],
     },],
   ],
 }