EDK: Add TaskRunner and PlatformHandleWatcher to RawChannel.

mojo/edk/system/slave_connection_manager.h

Index: mojo/edk/system/slave_connection_manager.h
diff --git a/mojo/edk/system/slave_connection_manager.h b/mojo/edk/system/slave_connection_manager.h
index 64e552c9ee8ec5ff89b398606fbe5aa626147fdc..54986a5aa98108ddd1f9f9adb93e4b60ed4be935 100644
--- a/mojo/edk/system/slave_connection_manager.h
+++ b/mojo/edk/system/slave_connection_manager.h
@@ -28,6 +28,7 @@ class SlaveProcessDelegate;
 }
 
 namespace platform {
+class PlatformHandleWatcher;
 class Thread;
 }
 
@@ -109,6 +110,7 @@ class SlaveConnectionManager final : public ConnectionManager,
   // TODO(vtl): This isn't really necessary.
   std::unique_ptr<platform::Thread> private_thread_;
   util::RefPtr<platform::TaskRunner> private_thread_task_runner_;
+  platform::PlatformHandleWatcher* private_thread_platform_handle_watcher_;
 
   // Only accessed on |private_thread_|:
   std::unique_ptr<RawChannel> raw_channel_;