[Sync] Convert sync to a static library.

components/sync/js/js_event_handler.h

Index: components/sync/js/js_event_handler.h
diff --git a/components/sync/js/js_event_handler.h b/components/sync/js/js_event_handler.h
index ec5a3e908040343f066a968b804ccbc79fa6b662..f1df13ebb8e94a96b684a971acba5fffff779b46 100644
--- a/components/sync/js/js_event_handler.h
+++ b/components/sync/js/js_event_handler.h
@@ -9,15 +9,13 @@
 
 #include <string>
 
-#include "components/sync/base/sync_export.h"
-
 namespace syncer {
 
 class JsEventDetails;
 
 // An interface for objects that handle Javascript events (e.g.,
 // WebUIs).
-class SYNC_EXPORT JsEventHandler {
+class JsEventHandler {
  public:
   virtual void HandleJsEvent(const std::string& name,
                              const JsEventDetails& details) = 0;