Introduce AttachmentStore metadata record

sync/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("//build/config/features.gni")
 
 component("sync") {
   public_deps = [
     ":sync_core",
     "//sync/protocol",
@@ skipping 386 matching lines @@
     "//base",
     "//base:i18n",
     "//base/third_party/dynamic_annotations",
     "//crypto",
     "//google_apis",
     "//net",
     "//sql",
     "//third_party/leveldatabase",
     "//third_party/zlib",
     "//url",
+    "//sync/internal_api/attachments/proto",
     "//sync/protocol",
   ]
 
   if (is_chromeos) {
     # Required by get_session_name.cc on Chrome OS.
     deps += [
       "//chromeos"
     ]
   }
 
@@ skipping 208 matching lines @@
 
   deps = [
     "//base",
     "//base/allocator",
     "//base/test:run_all_unittests",
     "//google_apis",
     "//google_apis:test_support",
     "//net",
     "//net:test_support",
     "//sql",
+    "//sync",
     "//testing/gmock",
     "//testing/gtest",
+    "//third_party/leveldatabase",
     "//third_party/protobuf:protobuf_lite",
-    "//sync",
     ":test_support_sync_core",
     ":test_support_sync_internal_api",
   ]
 
   # TODO(GYP)
   #   ['OS == "android"', {
   #     'dependencies': [
   #       '../testing/android/native_test.gyp:native_test_native_code',
   #     ],
   #   }],
@@ skipping 161 matching lines @@
   }
 
   # GYP: //sync/sync_tests.gypi:sync_unit_tests_apk
   unittest_apk("sync_unit_tests_apk") {
     unittests_dep = ":sync_unit_tests"
     deps =  [
       ":sync_unit_tests",
     ]
   }
 }