Revert of Mojo: Armed Watchers

mojo/edk/system/core.h

Index: mojo/edk/system/core.h
diff --git a/mojo/edk/system/core.h b/mojo/edk/system/core.h
index 2ef9b7f611aebd165110d46abf1addae0ecf9643..1e20a87a154586b3472d16201254c1d2518fd5fc 100644
--- a/mojo/edk/system/core.h
+++ b/mojo/edk/system/core.h
@@ -27,7 +27,6 @@
 #include "mojo/public/c/system/message_pipe.h"
 #include "mojo/public/c/system/platform_handle.h"
 #include "mojo/public/c/system/types.h"
-#include "mojo/public/c/system/watcher.h"
 #include "mojo/public/cpp/system/message_pipe.h"
 
 namespace base {
@@ -146,18 +145,11 @@
                       MojoDeadline deadline,
                       uint32_t* result_index,
                       MojoHandleSignalsState* signals_states);
-  MojoResult CreateWatcher(MojoWatcherCallback callback,
-                           MojoHandle* watcher_handle);
-  MojoResult Watch(MojoHandle watcher_handle,
-                   MojoHandle handle,
+  MojoResult Watch(MojoHandle handle,
                    MojoHandleSignals signals,
+                   MojoWatchCallback callback,
                    uintptr_t context);
-  MojoResult CancelWatch(MojoHandle watcher_handle, uintptr_t context);
-  MojoResult ArmWatcher(MojoHandle watcher_handle,
-                        uint32_t* num_ready_contexts,
-                        uintptr_t* ready_contexts,
-                        MojoResult* ready_results,
-                        MojoHandleSignalsState* ready_signals_states);
+  MojoResult CancelWatch(MojoHandle handle, uintptr_t context);
   MojoResult AllocMessage(uint32_t num_bytes,
                           const MojoHandle* handles,
                           uint32_t num_handles,