Use Mojo pipes to signal sync IPC events

components/nacl/loader/nacl_helper_linux.cc

Index: components/nacl/loader/nacl_helper_linux.cc
diff --git a/components/nacl/loader/nacl_helper_linux.cc b/components/nacl/loader/nacl_helper_linux.cc
index 1952cedf8942653adde200055b4fc58b127c54f1..d8ab926676a48616f5ee02a2f56be1e862711595 100644
--- a/components/nacl/loader/nacl_helper_linux.cc
+++ b/components/nacl/loader/nacl_helper_linux.cc
@@ -40,6 +40,7 @@
 #include "content/public/common/zygote_fork_delegate_linux.h"
 #include "ipc/ipc_descriptors.h"
 #include "ipc/ipc_switches.h"
+#include "mojo/edk/embedder/embedder.h"
 #include "sandbox/linux/services/credentials.h"
 #include "sandbox/linux/services/namespace_sandbox.h"
 
@@ -118,6 +119,9 @@ void BecomeNaClLoader(base::ScopedFD browser_fd,
   base::GlobalDescriptors::GetInstance()->Set(kPrimaryIPCChannel,
                                               browser_fd.release());
 
+  // The Mojo EDK must be initialized before using IPC.
+  mojo::edk::Init();
+
   base::MessageLoopForIO main_message_loop;
 #if defined(OS_NACL_NONSFI)
   CHECK(uses_nonsfi_mode);