[mojo-edk] Simplify multiprocess pipe bootstrap

mojo/edk/embedder/embedder.cc

Index: mojo/edk/embedder/embedder.cc
diff --git a/mojo/edk/embedder/embedder.cc b/mojo/edk/embedder/embedder.cc
index d1ab6c69d692be9f640bfb2df356fad29aa6531e..8a0d26b59958c643ac93c3ea081bee33e5f11512 100644
--- a/mojo/edk/embedder/embedder.cc
+++ b/mojo/edk/embedder/embedder.cc
@@ -107,15 +107,15 @@ void ShutdownIPCSupport() {
 
 ScopedMessagePipeHandle CreateMessagePipe(
     ScopedPlatformHandle platform_handle) {
-  NOTREACHED();
-  return ScopedMessagePipeHandle();
+  DCHECK(internal::g_core);
+  return internal::g_core->CreateMessagePipe(std::move(platform_handle));
 }
 
 void CreateMessagePipe(
     ScopedPlatformHandle platform_handle,
     const base::Callback<void(ScopedMessagePipeHandle)>& callback) {
   DCHECK(internal::g_core);
-  internal::g_core->CreateMessagePipe(std::move(platform_handle), callback);
+  callback.Run(CreateMessagePipe(std::move(platform_handle)));
 }
 
 void CreateParentMessagePipe(