Mojo: Add BindingsSupportImpl on top of HandleWatcher

mojo/common/bindings_support_impl.cc

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "mojo/common/bindings_support_impl.h"
+
+#include "base/bind.h"
+#include "mojo/common/handle_watcher.h"
+
+namespace mojo {
+namespace common {
+namespace {
+
+void CallOnHandleReady(HandleWatcher* watcher,
+                       BindingsSupport::AsyncWaitCallback* callback,
+                       MojoResult result) {
+  delete watcher;
+  callback->OnHandleReady(result);
+}
+
+}  // namespace
+
+BindingsSupportImpl::BindingsSupportImpl() {
+}
+
+BindingsSupportImpl::~BindingsSupportImpl() {
+}

[sky, 2013/11/08 16:44:02]

Is there a expectation that deleting BindingsSupportImpl implicitly cancels all
outstanding async waits?

+
+BindingsSupport::AsyncWaitID BindingsSupportImpl::AsyncWait(
+    Handle handle,
+    MojoWaitFlags flags,
+    AsyncWaitCallback* callback) {
+  HandleWatcher* watcher = new HandleWatcher();
+
+  // TODO(darin): Standardize on mojo::Handle instead of MojoHandle?
+  watcher->Start(handle.value,
+                 flags,
+                 MOJO_DEADLINE_INDEFINITE,
+                 base::Bind(&CallOnHandleReady, watcher, callback));
+  return watcher;
+}
+
+void BindingsSupportImpl::CancelWait(AsyncWaitID async_wait_id) {
+  HandleWatcher* watcher = static_cast<HandleWatcher*>(async_wait_id);

[sky, 2013/11/08 16:44:02]

I'm surprised you don't need reinterpret_cast here.

+  delete watcher;
+}
+
+}  // namespace common
+}  // namespace mojo