Rationalize AddAwakable...() and RemoveAwakable...() methods.

mojo/edk/system/message_pipe_endpoint.cc

Index: mojo/edk/system/message_pipe_endpoint.cc
diff --git a/mojo/edk/system/message_pipe_endpoint.cc b/mojo/edk/system/message_pipe_endpoint.cc
index 0211f8695adfe76edfa060eb50b1f6011bbd8725..42da701e92bb2984ac5a874ff624f932e11dea96 100644
--- a/mojo/edk/system/message_pipe_endpoint.cc
+++ b/mojo/edk/system/message_pipe_endpoint.cc
@@ -28,9 +28,9 @@ HandleSignalsState MessagePipeEndpoint::GetHandleSignalsState() const {
 }
 
 MojoResult MessagePipeEndpoint::AddAwakable(Awakable* /*awakable*/,
-                                            MojoHandleSignals /*signals*/,
-                                            bool /*force*/,
                                             uint64_t /*context*/,
+                                            bool /*force*/,
+                                            MojoHandleSignals /*signals*/,
                                             HandleSignalsState* signals_state) {
   NOTREACHED();
   if (signals_state)
@@ -38,22 +38,15 @@ MojoResult MessagePipeEndpoint::AddAwakable(Awakable* /*awakable*/,
   return MOJO_RESULT_INTERNAL;
 }
 
-void MessagePipeEndpoint::RemoveAwakable(Awakable* /*awakable*/,
+void MessagePipeEndpoint::RemoveAwakable(bool /*match_context*/,
+                                         Awakable* /*awakable*/,
+                                         uint64_t /*context*/,
                                          HandleSignalsState* signals_state) {
   NOTREACHED();
   if (signals_state)
     *signals_state = HandleSignalsState();
 }
 
-void MessagePipeEndpoint::RemoveAwakableWithContext(
-    Awakable* /*awakable*/,
-    uint64_t /*context*/,
-    HandleSignalsState* signals_state) {
-  NOTREACHED();
-  if (signals_state)
-    *signals_state = HandleSignalsState();
-}
-
 void MessagePipeEndpoint::Attach(ChannelEndpoint* /*channel_endpoint*/) {
   NOTREACHED();
 }