[sync] Componentize sync: Part Final: Target 'sync' is now its own component

sync/base/sync_export.h

Index: sync/base/sync_export.h
diff --git a/sync/base/sync_export.h b/sync/base/sync_export.h
index a38e8b23a365e01b1bee96c4985e07fa6f28a740..b2148a93e3021cfe8bf2b89a737875601a630023 100644
--- a/sync/base/sync_export.h
+++ b/sync/base/sync_export.h
@@ -1,12 +1,23 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright 2013 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.
 
 #ifndef SYNC_SYNC_EXPORT_H_
 #define SYNC_SYNC_EXPORT_H_
 
-// TODO(akalin): Remove '0 && ' when sync becomes a component.
-#if 0 && defined(COMPONENT_BUILD)
+// Notes:
+// 1) To make a symbol accessible from 'sync_unit_tests', but hidden from
+//    chrome components like 'browser', or from chrome test suites like
+//    'unit_tests' or 'sync_integration_tests', use SYNC_EXPORT_PRIVATE.
+// 2) To make a symbol accessible from chrome components, chrome test suites,
+//    and 'sync_unit_tests', use SYNC_EXPORT.
+// 3) Typically, if you need to add a 'sync/*' entry to a DEPS file outside
+//    'sync/', you will also need to export the class being used. Otherwise, you
+//    may see linker errors with a component build.
+// See http://www.chromium.org/developers/how-tos/component-build for more info.
+// TODO(rsimha): Include a link to a doc on sync componentization.

[Ryan Sleevi, 2013/01/23 04:06:21]

Is this comment necessary? Does it deviate at all from the 'normal'
componentization process?

It seems like this is just the same old API.

[Raghu Simha, 2013/01/23 08:04:06]

This is the same API as the other FOO_EXPORTs. Tim asked me to add a comment
here to help folks debug link errors. If you think this seems repetitive, I'll
let folks know offline.

+
+#if defined(COMPONENT_BUILD)
 #if defined(WIN32)
 
 #if defined(SYNC_IMPLEMENTATION)