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

mojo/edk/system/data_pipe_producer_dispatcher.cc

Index: mojo/edk/system/data_pipe_producer_dispatcher.cc
diff --git a/mojo/edk/system/data_pipe_producer_dispatcher.cc b/mojo/edk/system/data_pipe_producer_dispatcher.cc
index c9c686a140fa3e7bdb2d9e83829bcd37493ec881..c6696cd616557dcbfad913392d3824428a590912 100644
--- a/mojo/edk/system/data_pipe_producer_dispatcher.cc
+++ b/mojo/edk/system/data_pipe_producer_dispatcher.cc
@@ -169,29 +169,23 @@ HandleSignalsState DataPipeProducerDispatcher::GetHandleSignalsStateImplNoLock()
 
 MojoResult DataPipeProducerDispatcher::AddAwakableImplNoLock(
     Awakable* awakable,
-    MojoHandleSignals signals,
-    bool force,
     uint64_t context,
+    bool force,
+    MojoHandleSignals signals,
     HandleSignalsState* signals_state) {
   mutex().AssertHeld();
-  return data_pipe_->ProducerAddAwakable(awakable, signals, force, context,
+  return data_pipe_->ProducerAddAwakable(awakable, context, force, signals,
                                          signals_state);
 }
 
 void DataPipeProducerDispatcher::RemoveAwakableImplNoLock(
-    Awakable* awakable,
-    HandleSignalsState* signals_state) {
-  mutex().AssertHeld();
-  data_pipe_->ProducerRemoveAwakable(awakable, signals_state);
-}
-
-void DataPipeProducerDispatcher::RemoveAwakableWithContextImplNoLock(
+    bool match_context,
     Awakable* awakable,
     uint64_t context,
     HandleSignalsState* signals_state) {
   mutex().AssertHeld();
-  data_pipe_->ProducerRemoveAwakableWithContext(awakable, context,
-                                                signals_state);
+  data_pipe_->ProducerRemoveAwakable(match_context, awakable, context,
+                                     signals_state);
 }
 
 void DataPipeProducerDispatcher::StartSerializeImplNoLock(