Support mojo connections between unrelated peer processes.

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 8fb073524bb8033729e830e38691eccde4ed625e..3508ba3fc47167ed68fba90ac12eae9a69b9aac3 100644
--- a/mojo/edk/embedder/embedder.cc
+++ b/mojo/edk/embedder/embedder.cc
@@ -76,6 +76,12 @@ void SetParentPipeHandleFromCommandLine() {
   SetParentPipeHandle(std::move(platform_channel));
 }
 
+ScopedMessagePipeHandle ConnectToPeerProcess(ScopedPlatformHandle pipe) {
+  CHECK(internal::g_process_delegate);
+  DCHECK(pipe.is_valid());
+  return internal::g_core->ConnectToPeerProcess(std::move(pipe));
+}
+
 void Init() {
   MojoSystemThunks thunks = MakeSystemThunks();
   size_t expected_size = MojoEmbedderSetSystemThunks(&thunks);