Implement WiFi Display elementary stream packetizer.

extensions/renderer/api/display_source/wifi_display/wifi_display_stream_packet_part.h

Index: extensions/renderer/api/display_source/wifi_display/wifi_display_stream_packet_part.h
diff --git a/extensions/renderer/api/display_source/wifi_display/wifi_display_stream_packet_part.h b/extensions/renderer/api/display_source/wifi_display/wifi_display_stream_packet_part.h
new file mode 100644
index 0000000000000000000000000000000000000000..152b4a7ea230d98d25355c4f96c084bb9597b141
--- /dev/null
+++ b/extensions/renderer/api/display_source/wifi_display/wifi_display_stream_packet_part.h
@@ -0,0 +1,43 @@
+// Copyright 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 EXTENSIONS_RENDERER_API_DISPLAY_SOURCE_WIFI_DISPLAY_WIFI_DISPLAY_STREAM_PACKET_PART_H_
+#define EXTENSIONS_RENDERER_API_DISPLAY_SOURCE_WIFI_DISPLAY_WIFI_DISPLAY_STREAM_PACKET_PART_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "base/macros.h"
+
+namespace extensions {
+
+// WiFi Display elementary stream unit packetization consists of multiple
+// packetization phases. During those phases, unit buffer bytes are not
+// modified but only wrapped in packets.
+// This class allows different kind of WiFi Display stream packets to refer to
+// unit buffer bytes without copying them.
+class WiFiDisplayStreamPacketPart {
+ public:
+  WiFiDisplayStreamPacketPart(const uint8_t* data, size_t size)
+      : data_(data), size_(size) {}
+  template <size_t N>
+  explicit WiFiDisplayStreamPacketPart(const uint8_t (&data)[N])
+      : WiFiDisplayStreamPacketPart(data, N) {}
+
+  const uint8_t* begin() const { return data(); }
+  const uint8_t* data() const { return data_; }
+  bool empty() const { return size() == 0u; }
+  const uint8_t* end() const { return data() + size(); }
+  size_t size() const { return size_; }
+
+ private:
+  const uint8_t* const data_;
+  const size_t size_;
+
+  DISALLOW_COPY_AND_ASSIGN(WiFiDisplayStreamPacketPart);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_RENDERER_API_DISPLAY_SOURCE_WIFI_DISPLAY_WIFI_DISPLAY_STREAM_PACKET_BASE_H_