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

mojo/edk/system/dispatcher_unittest.cc

Index: mojo/edk/system/dispatcher_unittest.cc
diff --git a/third_party/mojo/src/mojo/edk/system/dispatcher_unittest.cc b/mojo/edk/system/dispatcher_unittest.cc
similarity index 99%
copy from third_party/mojo/src/mojo/edk/system/dispatcher_unittest.cc
copy to mojo/edk/system/dispatcher_unittest.cc
index c6431ffea7b71302fad99b0bcbe46003b5afd2d2..10c2b862fb8038926d554a4de3a8f988c77e49dc 100644
--- a/third_party/mojo/src/mojo/edk/system/dispatcher_unittest.cc
+++ b/mojo/edk/system/dispatcher_unittest.cc
@@ -31,7 +31,7 @@ class TrivialDispatcher final : public Dispatcher {
 
   scoped_refptr<Dispatcher> CreateEquivalentDispatcherAndCloseImplNoLock()
       override {
-    mutex().AssertHeld();
+    lock().AssertAcquired();
     return scoped_refptr<Dispatcher>(new TrivialDispatcher());
   }