Add opus audio codec support in remoting

third_party/opus/overrides/include/opus_defines.h

Index: third_party/opus/overrides/include/opus_defines.h
diff --git a/third_party/opus/overrides/include/opus_defines.h b/third_party/opus/overrides/include/opus_defines.h
new file mode 100644
index 0000000000000000000000000000000000000000..290bc9152283ff254543b85950170bbb30d53d5e
--- /dev/null
+++ b/third_party/opus/overrides/include/opus_defines.h
@@ -0,0 +1,19 @@
+// 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.
+
+#include "base/stringize_macros.h"
+
+// HACK: This is a hack to make sure that we don't export opus symbols.
+// opus_defines.h sets OPUS_EXPORT only when OPUS_BUILD is defined.
+#if defined(OPUS_BUILD)
+#undef OPUS_BUILD
+#define OPUS_BUILD_DEFINED
+#endif  // defined(OPUS_BUILD)
+
+#include "third_party/opus/src/include/opus_defines.h"
+
+#if defined(OPUS_BUILD_DEFINED)
+#undef OPUS_BUILD_DEFINED
+#define OPUS_BUILD
+#endif  // defined(OPUS_BUILD_DEFINED)