EDK: Remove MOJO_SYSTEM_IMPL_EXPORT, system_impl_export.h, etc.

mojo/edk/system/incoming_endpoint.h

Index: mojo/edk/system/incoming_endpoint.h
diff --git a/mojo/edk/system/incoming_endpoint.h b/mojo/edk/system/incoming_endpoint.h
index bf0acf34dfef0b530d1b2a85b961402d92afecfa..efb85a4a4a2da68a475e0939bed59075f1c588c5 100644
--- a/mojo/edk/system/incoming_endpoint.h
+++ b/mojo/edk/system/incoming_endpoint.h
@@ -11,7 +11,6 @@
 #include "mojo/edk/system/channel_endpoint_client.h"
 #include "mojo/edk/system/message_in_transit_queue.h"
 #include "mojo/edk/system/mutex.h"
-#include "mojo/edk/system/system_impl_export.h"
 #include "mojo/public/cpp/system/macros.h"
 
 struct MojoCreateDataPipeOptions;
@@ -26,8 +25,7 @@ class MessagePipe;
 // This is a simple |ChannelEndpointClient| that only receives messages. It's
 // used for endpoints that are "received" by |Channel|, but not yet turned into
 // |MessagePipe|s or |DataPipe|s.
-class MOJO_SYSTEM_IMPL_EXPORT IncomingEndpoint final
-    : public ChannelEndpointClient {
+class IncomingEndpoint final : public ChannelEndpointClient {
  public:
   IncomingEndpoint();