Refactor audio and video decoder status into common file.

media/base/decoder_status.h

Index: media/base/decoder_status.h
diff --git a/media/base/decoder_status.h b/media/base/decoder_status.h
new file mode 100644
index 0000000000000000000000000000000000000000..53244b284fd5573806cf533eb2f198922ea18dc9
--- /dev/null
+++ b/media/base/decoder_status.h
@@ -0,0 +1,26 @@
+// Copyright 2016 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 MEDIA_BASE_DECODER_STATUS_H_
+#define MEDIA_BASE_DECODER_STATUS_H_
+
+#include <ostream>

[xhwang, 2016/03/29 19:42:28]

Will "#include <iosfwd>" work?

See example:
https://code.google.com/p/chromium/codesearch#chromium/src/base/strings/strin...

[DaleCurtis, 2016/03/30 00:34:19]

Done.

+
+#include "media/base/media_export.h"
+
+namespace media {
+
+enum class DecoderStatus {

[xhwang, 2016/03/29 19:42:28]

Since this the status of the "decode" operation, not the general state/status of
the "decoder". Should it be named "DecodeStatus"?

Note that in mojo we actually use interfaces::AudioDecoder::DecodeStatus.

[DaleCurtis, 2016/03/30 00:34:19]

Renamed to DecodeStatus.

+  OK = 0,        // Everything went as planned.
+  ABORTED,       // Read aborted due to Reset() during pending read.
+  DECODE_ERROR,  // Decoder returned decode error.

[xhwang, 2016/03/29 19:42:28]

The "DECODE" part seems redundant but apparently "ERROR" is defined as a special
macro on Windows. Shall we document it so people won't ask again?

Well, it won't look redundant when you add other error types. So totally up to
you :)

[DaleCurtis, 2016/03/30 00:34:19]

Done.

+};
+
+// Helper function so that DecoderStatus can be printed easily.
+MEDIA_EXPORT std::ostream& operator<<(std::ostream& os,
+                                      const DecoderStatus& status);
+
+}  // namespace media
+
+#endif  // MEDIA_BASE_DECODER_STATUS_H_