Always leak the Mojo parent pipe handle on child process shutdown.

mojo/edk/system/node_channel.h

Index: mojo/edk/system/node_channel.h
diff --git a/mojo/edk/system/node_channel.h b/mojo/edk/system/node_channel.h
index 08f95633e29ada9b5ea47b14e4e509da81540cb7..e06a2334872e6ed39d5b41e2d4d6aec879410f25 100644
--- a/mojo/edk/system/node_channel.h
+++ b/mojo/edk/system/node_channel.h
@@ -101,6 +101,9 @@ class NodeChannel : public base::RefCountedThreadSafe<NodeChannel>,
   // Permanently stop the channel from sending or receiving messages.
   void ShutDown();
 
+  // Leaks the pipe handle instead of closing it on shutdown.
+  void LeakHandleOnShutdown();
+
   // Invokes the bad message callback for this channel, if any.
   void NotifyBadMessage(const std::string& error);