Begin refactor of AVDA to support zero-copy.

content/common/gpu/media/avda_return_on_failure.h

+// Copyright (c) 2015 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_GPU_MEDIA_AVDA_RETURN_ON_FAILURE_H_
+#define CONTENT_COMMON_GPU_MEDIA_AVDA_RETURN_ON_FAILURE_H_
+
+#include "media/video/video_decode_accelerator.h"
+
+// Helper macros for dealing with failure.  If |result| evaluates false, emit
+// |log| to ERROR, register |error| with the decoder, and return.  This will
+// also transition to the error state, stopping further decoding.
+// This is meant to be used only within AndroidVideoDecoderBase and its
+// various subclasses.  |provider| must support PostError.

[watk, 2015/09/09 00:36:01]

Comment is out of date already :P

+#define RETURN_ON_FAILURE(provider, result, log, error)               \
+  do {                                                                \
+    if (!(result)) {                                                  \
+      DLOG(ERROR) << log;                                             \
+      provider->PostError(FROM_HERE,                                  \
+                          media::VideoDecodeAccelerator::error);      \
+      return;                                                         \
+    }                                                                 \
+  } while (0)
+
+#endif  // CONTENT_COMMON_GPU_MEDIA_AVDA_RETURN_ON_FAILURE_H_