AwakableList: For persistent awakables, make Add() call Awake() with reason INITIALIZE.

mojo/edk/system/local_message_pipe_endpoint.cc

Index: mojo/edk/system/local_message_pipe_endpoint.cc
diff --git a/mojo/edk/system/local_message_pipe_endpoint.cc b/mojo/edk/system/local_message_pipe_endpoint.cc
index 77088855e6adb20c60ba986bff665cee97633e53..7c648f4b3db16f01408baad7d586a99e8ba24eed 100644
--- a/mojo/edk/system/local_message_pipe_endpoint.cc
+++ b/mojo/edk/system/local_message_pipe_endpoint.cc
@@ -159,19 +159,18 @@ MojoResult LocalMessagePipeEndpoint::AddAwakable(
   HandleSignalsState state = GetHandleSignalsState();
   if (signals_state)
     *signals_state = state;
-  if (state.satisfies(signals)) {
-    if (persistent)
-      awakable_list_.Add(awakable, context, persistent, signals);
-    return MOJO_RESULT_ALREADY_EXISTS;
-  }
-  if (!state.can_satisfy(signals)) {
-    if (persistent)
-      awakable_list_.Add(awakable, context, persistent, signals);
-    return MOJO_RESULT_FAILED_PRECONDITION;
-  }
+  MojoResult rv = MOJO_RESULT_OK;
+  bool should_add = persistent;
+  if (state.satisfies(signals))
+    rv = MOJO_RESULT_ALREADY_EXISTS;
+  else if (!state.can_satisfy(signals))
+    rv = MOJO_RESULT_FAILED_PRECONDITION;
+  else
+    should_add = true;
 
-  awakable_list_.Add(awakable, context, persistent, signals);
-  return MOJO_RESULT_OK;
+  if (should_add)
+    awakable_list_.Add(awakable, context, persistent, signals, state);
+  return rv;
 }
 
 void LocalMessagePipeEndpoint::RemoveAwakable(