PPAPI: Make blocking completion callbacks work.

ppapi/shared_impl/api_callback_type.h

Index: ppapi/shared_impl/api_callback_type.h
diff --git a/ppapi/shared_impl/api_callback_type.h b/ppapi/shared_impl/api_callback_type.h
new file mode 100644
index 0000000000000000000000000000000000000000..7f6f7aed79bbbd5baa6c8821c70e73fe16cc00c5
--- /dev/null
+++ b/ppapi/shared_impl/api_callback_type.h
@@ -0,0 +1,17 @@
+// Copyright (c) 2012 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.
+
+#ifndef PPAPI_SHARED_IMPL_API_CALLBACK_TYPE_H_
+#define PPAPI_SHARED_IMPL_API_CALLBACK_TYPE_H_
+
+#include "base/memory/ref_counted.h"
+#include "ppapi/shared_impl/tracked_callback.h"
+
+namespace ppapi {
+
+typedef scoped_refptr<TrackedCallback> ApiCallbackType;

[brettw, 2012/04/20 18:24:29]

Personally, I find using this to be less clear than just referencing
scoped_refptr. The scoped_refptr isn't that long and this is both an extra file
and requires that I look up the typedef to figure out what the type is. It feels
like somebody reading this shouldn't have to look under so many rocks to figure
out what's happening.

[dmichael (off chromium), 2012/05/16 22:18:34]

Yeah, I agree. I was:
(1) afraid I'd have to change it (if this didn't work, or we didn't want a
dependence from ppapi/thunk to base for some reason, or we wanted to pass by
const-ref, etc).
(2) Too lazy to want to reformat that much code if I didn't have to :-)

Done.

+
+}  // namespace ppapi
+
+#endif  // PPAPI_SHARED_IMPL_API_CALLBACK_TYPE_H_