Revert of Mojo: Armed Watchers

mojo/edk/system/awakable_list.h

Index: mojo/edk/system/awakable_list.h
diff --git a/mojo/edk/system/awakable_list.h b/mojo/edk/system/awakable_list.h
index 34d6b06922a041498d06a7d155c1124f4a8922d7..355677f7036771af72221e0ceee8d9d7c09b6f60 100644
--- a/mojo/edk/system/awakable_list.h
+++ b/mojo/edk/system/awakable_list.h
@@ -12,6 +12,8 @@
 
 #include "base/macros.h"
 #include "mojo/edk/system/system_impl_export.h"
+#include "mojo/edk/system/watcher.h"
+#include "mojo/edk/system/watcher_set.h"
 #include "mojo/public/c/system/types.h"
 
 namespace mojo {
@@ -37,6 +39,13 @@
   void Add(Awakable* awakable, MojoHandleSignals signals, uintptr_t context);
   void Remove(Awakable* awakable);
 
+  // Add and remove Watchers to this AwakableList.
+  MojoResult AddWatcher(MojoHandleSignals signals,
+                        const Watcher::WatchCallback& callback,
+                        uintptr_t context,
+                        const HandleSignalsState& current_state);
+  MojoResult RemoveWatcher(uintptr_t context);
+
  private:
   struct AwakeInfo {
     AwakeInfo(Awakable* awakable, MojoHandleSignals signals, uintptr_t context)
@@ -50,6 +59,10 @@
 
   AwakeInfoList awakables_;
 
+  // TODO: Remove AwakableList and instead use WatcherSet directly in
+  // dispatchers.
+  WatcherSet watchers_;
+
   DISALLOW_COPY_AND_ASSIGN(AwakableList);
 };