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

mojo/edk/embedder/simple_platform_shared_buffer_posix.cc

Index: mojo/edk/embedder/simple_platform_shared_buffer_posix.cc
diff --git a/third_party/mojo/src/mojo/edk/embedder/simple_platform_shared_buffer_posix.cc b/mojo/edk/embedder/simple_platform_shared_buffer_posix.cc
similarity index 99%
copy from third_party/mojo/src/mojo/edk/embedder/simple_platform_shared_buffer_posix.cc
copy to mojo/edk/embedder/simple_platform_shared_buffer_posix.cc
index 4bae02e26d9566532a8b5257f921ab02c327c50f..6914b39ffe7fad1ad52ec8639921bd83a08c006b 100644
--- a/third_party/mojo/src/mojo/edk/embedder/simple_platform_shared_buffer_posix.cc
+++ b/mojo/edk/embedder/simple_platform_shared_buffer_posix.cc
@@ -28,7 +28,7 @@ static_assert(sizeof(size_t) <= sizeof(uint64_t), "size_t too big");
 static_assert(sizeof(off_t) <= sizeof(uint64_t), "off_t too big");
 
 namespace mojo {
-namespace embedder {
+namespace edk {
 
 // SimplePlatformSharedBuffer --------------------------------------------------
 
@@ -154,5 +154,5 @@ void SimplePlatformSharedBufferMapping::Unmap() {
   PLOG_IF(ERROR, result != 0) << "munmap";
 }
 
-}  // namespace embedder
+}  // namespace edk
 }  // namespace mojo