Support error handling for Surface readbacks

content/public/browser/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_
+#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_NOT_SUPPORTED,
+  READBACK_SURFACE_UNAVAILABLE,
+  READBACK_MEMORY_ALLOCATION_FAILURE,
+};
+
+typedef const base::Callback<void(const SkBitmap&, ReadbackResponse)>
+    ReadbackRequestCallback;
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_READBACK_TYPES_H_