Support error handling for Surface readbacks

content/common/readback_types.h

+// Copyright 2014 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 CONTENT_COMMON_READBACK_TYPES_H_

[piman, 2014/10/02 18:08:26]

This file should go into content/public/browser, so that it can be used by
extensions/.

[sivag, 2014/11/06 13:34:16]

Done.

+#define CONTENT_COMMON_READBACK_TYPES_H_
+
+#include "base/callback.h"
+
+class SkBitmap;
+
+namespace content {
+
+enum ReadbackResponse {
+  READBACK_SUCCESS,
+  READBACK_FAILED,
+  READBACK_FORMAT_NOT_SUPPORTED,
+  READBACK_NOTSUPPORTED,

[piman, 2014/10/02 18:08:26]

nit: NOT_SUPPORTED ?

[sivag, 2014/11/06 13:34:16]

Done.

+  READBACK_SURFACE_UNAVAILABLE,
+  READBACK_RESULT_EMPTY,

[piman, 2014/10/02 18:08:26]

I don't think we need both RESULT_EMPTY and FAILED. We get an empty bitmap from
the compositor when the readback fails (e.g. the layer was removed from the
tree)

[sivag, 2014/11/06 13:34:16]

Done.

+  READBACK_MEMORY_ALLOCATION_FAILURE,
+};
+
+typedef const base::Callback<void(bool, const SkBitmap&, const int&)>

[piman, 2014/10/02 18:08:26]

Why int instead of ReadbackResponse?

[piman, 2014/10/02 18:08:26]

We shouldn't need both the bool and the ReadbackResponse.

[sivag, 2014/11/06 13:34:16]

Done.

[sivag, 2014/11/06 13:34:16]

Done.

+    CopyFromCompositingSurfaceCallback;

[piman, 2014/10/02 18:08:26]

We should be consistent in the naming, "Copy" vs "Readback"

[sivag, 2014/11/06 13:34:16]

Done.

+
+}  // namespace
+
+#endif  // CONTENT_COMMON_READBACK_TYPES_H_