sync: Buffer Protocol Events for about:sync page

sync/internal_api/public/events/poll_get_updates_request_event.h

Index: sync/internal_api/public/events/poll_get_updates_request_event.h
diff --git a/sync/internal_api/public/events/poll_get_updates_request_event.h b/sync/internal_api/public/events/poll_get_updates_request_event.h
index d4a679ce5da3a876f01a5d211b015be57e592003..f039c1de92d5e988d3a5d87b94a9de47e9dac5b6 100644
--- a/sync/internal_api/public/events/poll_get_updates_request_event.h
+++ b/sync/internal_api/public/events/poll_get_updates_request_event.h
@@ -8,6 +8,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "base/values.h"
+#include "sync/base/sync_export.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/internal_api/public/events/protocol_event.h"
 #include "sync/protocol/sync.pb.h"
@@ -19,7 +20,7 @@ class NudgeTracker;
 }  // namespace sessions
 
 // An event representing a poll request sent to the server.
-class PollGetUpdatesRequestEvent : public ProtocolEvent {
+class SYNC_EXPORT_PRIVATE PollGetUpdatesRequestEvent : public ProtocolEvent {
  public:
   PollGetUpdatesRequestEvent(
       base::Time timestamp,