EDK: Remove MOJO_SYSTEM_IMPL_EXPORT, system_impl_export.h, etc.

mojo/edk/system/local_data_pipe_impl.h

Index: mojo/edk/system/local_data_pipe_impl.h
diff --git a/mojo/edk/system/local_data_pipe_impl.h b/mojo/edk/system/local_data_pipe_impl.h
index 2564a017954c603ec2389a7806112ff6ed13d664..46a353d72526876d6b3b50114d2309812a001f20 100644
--- a/mojo/edk/system/local_data_pipe_impl.h
+++ b/mojo/edk/system/local_data_pipe_impl.h
@@ -9,7 +9,6 @@
 
 #include "base/memory/aligned_memory.h"
 #include "mojo/edk/system/data_pipe_impl.h"
-#include "mojo/edk/system/system_impl_export.h"
 #include "mojo/public/cpp/system/macros.h"
 
 namespace mojo {
@@ -20,7 +19,7 @@ class MessageInTransitQueue;
 // |LocalDataPipeImpl| is a subclass that "implements" |DataPipe| for data pipes
 // whose producer and consumer are both local. See |DataPipeImpl| for more
 // details.
-class MOJO_SYSTEM_IMPL_EXPORT LocalDataPipeImpl final : public DataPipeImpl {
+class LocalDataPipeImpl final : public DataPipeImpl {
  public:
   LocalDataPipeImpl();
   ~LocalDataPipeImpl() override;