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

mojo/edk/system/async_waiter.cc

Index: mojo/edk/system/async_waiter.cc
diff --git a/third_party/mojo/src/mojo/edk/system/async_waiter.cc b/mojo/edk/system/async_waiter.cc
similarity index 92%
copy from third_party/mojo/src/mojo/edk/system/async_waiter.cc
copy to mojo/edk/system/async_waiter.cc
index 4f539b9cfcfc14f6a257a4767929d7ac3754b00b..d2e7000fb3879f43b2dbeeae2fb7ca3d2df28593 100644
--- a/third_party/mojo/src/mojo/edk/system/async_waiter.cc
+++ b/mojo/edk/system/async_waiter.cc
@@ -5,7 +5,7 @@
 #include "mojo/edk/system/async_waiter.h"
 
 namespace mojo {
-namespace system {
+namespace edk {
 
 AsyncWaiter::AsyncWaiter(const AwakeCallback& callback) : callback_(callback) {
 }
@@ -19,5 +19,5 @@ bool AsyncWaiter::Awake(MojoResult result, uintptr_t context) {
   return false;
 }
 
-}  // namespace system
+}  // namespace edk
 }  // namespace mojo