Revert of Mojo: Armed Watchers

mojo/edk/system/data_pipe_producer_dispatcher.h

Index: mojo/edk/system/data_pipe_producer_dispatcher.h
diff --git a/mojo/edk/system/data_pipe_producer_dispatcher.h b/mojo/edk/system/data_pipe_producer_dispatcher.h
index e47299417f33a22cd9b8d54317d8542c2af1c8a3..a55234a1dfe468683ebff5110176d8a2d6a57fc6 100644
--- a/mojo/edk/system/data_pipe_producer_dispatcher.h
+++ b/mojo/edk/system/data_pipe_producer_dispatcher.h
@@ -19,7 +19,6 @@
 #include "mojo/edk/system/dispatcher.h"
 #include "mojo/edk/system/ports/port_ref.h"
 #include "mojo/edk/system/system_impl_export.h"
-#include "mojo/edk/system/watcher_set.h"
 
 namespace mojo {
 namespace edk {
@@ -44,6 +43,10 @@
   // Dispatcher:
   Type GetType() const override;
   MojoResult Close() override;
+  MojoResult Watch(MojoHandleSignals signals,
+                   const Watcher::WatchCallback& callback,
+                   uintptr_t context) override;
+  MojoResult CancelWatch(uintptr_t context) override;
   MojoResult WriteData(const void* elements,
                        uint32_t* num_bytes,
                        MojoReadDataFlags flags) override;
@@ -52,10 +55,6 @@
                             MojoWriteDataFlags flags) override;
   MojoResult EndWriteData(uint32_t num_bytes_written) override;
   HandleSignalsState GetHandleSignalsState() const override;
-  MojoResult AddWatcherRef(const scoped_refptr<WatcherDispatcher>& watcher,
-                           uintptr_t context) override;
-  MojoResult RemoveWatcherRef(WatcherDispatcher* watcher,
-                              uintptr_t context) override;
   MojoResult AddAwakable(Awakable* awakable,
                          MojoHandleSignals signals,
                          uintptr_t context,
@@ -105,7 +104,6 @@
   mutable base::Lock lock_;
 
   AwakableList awakable_list_;
-  WatcherSet watchers_;
 
   bool buffer_requested_ = false;