Introduce shared_memory_support media target for PPAPI

media/audio/shared_memory_util.h

Index: media/audio/shared_memory_util.h
diff --git a/media/audio/shared_memory_util.h b/media/audio/shared_memory_util.h
new file mode 100644
index 0000000000000000000000000000000000000000..d0227d9e3e9d5b388bcf3dd6334676a6ace511b4
--- /dev/null
+++ b/media/audio/shared_memory_util.h
@@ -0,0 +1,39 @@
+// 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.
+
+#ifndef MEDIA_AUDIO_SHARED_MEMORY_UTIL_H_
+#define MEDIA_AUDIO_SHARED_MEMORY_UTIL_H_
+
+#include "base/basictypes.h"
+#include "base/shared_memory.h"
+#include "media/base/media_export.h"
+
+namespace media {
+
+// Value sent by the controller to the renderer in low-latency mode
+// indicating that the stream is paused.
+enum { kPauseMark = -1 };
+
+// Functions that handle data buffer passed between processes in the shared
+// memory.  Called on both IPC sides.  These are necessary because the shared
+// memory has a layout: the last word in the block is the data size in bytes.
+
+MEDIA_EXPORT uint32 TotalSharedMemorySizeInBytes(uint32 packet_size);
+MEDIA_EXPORT uint32 PacketSizeInBytes(uint32 shared_memory_created_size);
+MEDIA_EXPORT uint32 GetActualDataSizeInBytes(base::SharedMemory* shared_memory,
+                                             uint32 shared_memory_size);
+MEDIA_EXPORT void SetActualDataSizeInBytes(base::SharedMemory* shared_memory,
+                                           uint32 shared_memory_size,
+                                           uint32 actual_data_size);
+MEDIA_EXPORT void SetActualDataSizeInBytes(void* shared_memory_ptr,
+                                           uint32 shared_memory_size,
+                                           uint32 actual_data_size);
+MEDIA_EXPORT void SetUnknownDataSize(base::SharedMemory* shared_memory,
+                                     uint32 shared_memory_size);
+MEDIA_EXPORT bool IsUnknownDataSize(base::SharedMemory* shared_memory,
+                                    uint32 shared_memory_size);
+
+}  // namespace media
+
+#endif  // MEDIA_AUDIO_SHARED_MEMORY_UTIL_H_