Split mojo_system dylib into public and private

mojo/system/local_message_pipe_endpoint.h

Index: mojo/system/local_message_pipe_endpoint.h
diff --git a/mojo/system/local_message_pipe_endpoint.h b/mojo/system/local_message_pipe_endpoint.h
index fd3f7b9c01178c9f6485defb0b6062d3f64aeefe..e8cc6e26f0a889365f2a36997d400c1a12aca1ec 100644
--- a/mojo/system/local_message_pipe_endpoint.h
+++ b/mojo/system/local_message_pipe_endpoint.h
@@ -11,14 +11,15 @@
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "mojo/public/system/core.h"
-#include "mojo/public/system/system_export.h"
 #include "mojo/system/message_pipe_endpoint.h"
+#include "mojo/system/system_impl_export.h"
 #include "mojo/system/waiter_list.h"
 
 namespace mojo {
 namespace system {
 
-class MOJO_SYSTEM_EXPORT LocalMessagePipeEndpoint : public MessagePipeEndpoint {
+class MOJO_SYSTEM_IMPL_EXPORT LocalMessagePipeEndpoint
+    : public MessagePipeEndpoint {
  public:
   LocalMessagePipeEndpoint();
   virtual ~LocalMessagePipeEndpoint();