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

mojo/edk/embedder/platform_channel_utils_posix.cc

Index: mojo/edk/embedder/platform_channel_utils_posix.cc
diff --git a/third_party/mojo/src/mojo/edk/embedder/platform_channel_utils_posix.cc b/mojo/edk/embedder/platform_channel_utils_posix.cc
similarity index 99%
copy from third_party/mojo/src/mojo/edk/embedder/platform_channel_utils_posix.cc
copy to mojo/edk/embedder/platform_channel_utils_posix.cc
index 61b573bda4bf431d8e320dd3c0329becd28c2abf..4af45e82c51727bd78adba8d71a1781918d04eb1 100644
--- a/third_party/mojo/src/mojo/edk/embedder/platform_channel_utils_posix.cc
+++ b/mojo/edk/embedder/platform_channel_utils_posix.cc
@@ -13,7 +13,7 @@
 #include "build/build_config.h"
 
 namespace mojo {
-namespace embedder {
+namespace edk {
 
 // On Linux, |SIGPIPE| is suppressed by passing |MSG_NOSIGNAL| to
 // |send()|/|sendmsg()|. (There is no way of suppressing |SIGPIPE| on
@@ -182,5 +182,5 @@ ssize_t PlatformChannelRecvmsg(PlatformHandle h,
   return result;
 }
 
-}  // namespace embedder
+}  // namespace edk
 }  // namespace mojo