[sync] Componentize sync: Part 2: Add SYNC_EXPORTs to files in src/sync/

sync/js/js_event_handler.h

Index: sync/js/js_event_handler.h
diff --git a/sync/js/js_event_handler.h b/sync/js/js_event_handler.h
index 04eadcadec0b37299fc599453180e9485d37d00e..2e2213efefbbbb30932a81c28e16a20ccbfcc5f7 100644
--- a/sync/js/js_event_handler.h
+++ b/sync/js/js_event_handler.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -9,13 +9,15 @@
 
 #include <string>
 
+#include "sync/base/sync_export.h"
+
 namespace syncer {
 
 class JsEventDetails;
 
 // An interface for objects that handle Javascript events (e.g.,
 // WebUIs).
-class JsEventHandler {
+class SYNC_EXPORT JsEventHandler {
  public:
   virtual void HandleJsEvent(
       const std::string& name, const JsEventDetails& details) = 0;