[Sync] Add sync_export.h (Step 1 for componentizing sync)

sync/sync.gyp

 # Copyright (c) 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': {
     'chromium_code': 1,
   },
   'targets': [
     # The core sync library.
     #
     # TODO(akalin): Rename this to something like 'sync_core' and
     # reserve the 'sync' name for the overarching library that clients
     # should depend on.
     {
       'target_name': 'sync',
+      # TODO(akalin): Change this to '<(component)'.  When we rename
+      # this to 'sync_core' and make the overarching 'sync' library,
+      # make that one '<(component)'.
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
       'include_dirs': [
         '..',
       ],
+      'defines': [
+        'SYNC_IMPLEMENTATION',
+      ],
       'dependencies': [
         '../base/base.gyp:base',
         '../build/temp_gyp/googleurl.gyp:googleurl',
         '../crypto/crypto.gyp:crypto',
         '../net/net.gyp:net',
         '../sql/sql.gyp:sql',
         'protocol/sync_proto.gyp:sync_proto',
       ],
       'export_dependent_settings': [
         # Propagate sync_proto since our headers include its generated
         # files.
         'protocol/sync_proto.gyp:sync_proto',
       ],
       'sources': [
+        'base/sync_export.h',
         'internal_api/public/base/enum_set.h',
         'internal_api/public/base/model_type.h',
         'internal_api/public/base/model_type_payload_map.cc',
         'internal_api/public/base/model_type_payload_map.h',
         'internal_api/public/engine/model_safe_worker.cc',
         'internal_api/public/engine/model_safe_worker.h',
         'internal_api/public/engine/passive_model_worker.cc',
         'internal_api/public/engine/passive_model_worker.h',
         'internal_api/public/engine/polling_constants.cc',
         'internal_api/public/engine/polling_constants.h',
@@ skipping 732 matching lines @@
       ],
       'sources': [
         'tools/sync_listen_notifications.cc',
       ],
     },
 
     # A standalone command-line sync client.
     {
       'target_name': 'sync_client',
       'type': 'executable',
+      'defines': [
+        'SYNC_TEST',
+      ],
       'dependencies': [
         '../base/base.gyp:base',
         '../jingle/jingle.gyp:notifier',
         '../net/net.gyp:net',
         '../net/net.gyp:net_test_support',
         'sync',
         'sync_notifier',
         'syncapi_core',
       ],
       'sources': [
@@ skipping 17 matching lines @@
             'test_suite_name': 'sync_unit_tests',
             'input_shlib_path': '<(SHARED_LIB_DIR)/<(SHARED_LIB_PREFIX)sync_unit_tests<(SHARED_LIB_SUFFIX)',
             'input_jars_paths': [ '<(PRODUCT_DIR)/lib.java/chromium_base.jar', ],
           },
           'includes': [ '../build/apk_test.gypi' ],
         },
       ],
     }],
   ],
 }