Add a Mojo EDK for Chrome that uses one OS pipe per message pipe.

mojo/edk/system/handle_signals_state.h

Index: mojo/edk/system/handle_signals_state.h
diff --git a/third_party/mojo/src/mojo/edk/system/handle_signals_state.h b/mojo/edk/system/handle_signals_state.h
similarity index 80%
copy from third_party/mojo/src/mojo/edk/system/handle_signals_state.h
copy to mojo/edk/system/handle_signals_state.h
index bec6e74b0d810f1f8186c423d7612c5f067c0868..1c47a288c1e27914798e2f8395f2122b873a5172 100644
--- a/third_party/mojo/src/mojo/edk/system/handle_signals_state.h
+++ b/mojo/edk/system/handle_signals_state.h
@@ -2,14 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef THIRD_PARTY_MOJO_SRC_MOJO_EDK_SYSTEM_HANDLE_SIGNALS_STATE_H_
-#define THIRD_PARTY_MOJO_SRC_MOJO_EDK_SYSTEM_HANDLE_SIGNALS_STATE_H_
+#ifndef MOJO_EDK_SYSTEM_HANDLE_SIGNALS_STATE_H_
+#define MOJO_EDK_SYSTEM_HANDLE_SIGNALS_STATE_H_
 
+#include "mojo/edk/system/system_impl_export.h"
 #include "mojo/public/c/system/types.h"
-#include "third_party/mojo/src/mojo/edk/system/system_impl_export.h"
 
 namespace mojo {
-namespace system {
+namespace edk {
 
 // Just "add" some constructors and methods to the C struct
 // |MojoHandleSignalsState| (for convenience). This should add no overhead.
@@ -43,7 +43,7 @@ struct MOJO_SYSTEM_IMPL_EXPORT HandleSignalsState final
 static_assert(sizeof(HandleSignalsState) == sizeof(MojoHandleSignalsState),
               "HandleSignalsState should add no overhead");
 
-}  // namespace system
+}  // namespace edk
 }  // namespace mojo
 
-#endif  // THIRD_PARTY_MOJO_SRC_MOJO_EDK_SYSTEM_HANDLE_SIGNALS_STATE_H_
+#endif  // MOJO_EDK_SYSTEM_HANDLE_SIGNALS_STATE_H_