Reland "Added ACM_dump protobuf, class for reading/writing and..."

webrtc/modules/audio_coding/main/acm2/dump.proto

+syntax = "proto2";
+option optimize_for = LITE_RUNTIME;
+package webrtc;
+
+// This is the main message to dump to a file, it can contain multiple event
+// messages, but it is possible to append multiple EventStreams (each with a
+// single event) to a file.
+// This has the benefit that there's no need to keep all data in memory.
+message ACMDumpEventStream {
+  repeated ACMDumpEvent stream = 1;
+}
+
+message ACMDumpEvent {
+  // required - Elapsed wallclock time in us since the start of the log.
+  optional int64 timestamp_us = 1;
+
+  // The different types of events that can occur, the UNKNOWN_EVENT entry
+  // is added in case future EventTypes are added, in that case old code will
+  // receive the new events as UNKNOWN_EVENT.
+  enum EventType {
+    UNKNOWN_EVENT = 0;
+    RTP_EVENT = 1;
+    DEBUG_EVENT = 2;
+  }
+
+  // required - Indicates the type of this event
+  optional EventType type = 2;
+
+  // optional - but required if type == RTP_EVENT
+  optional ACMDumpRTPPacket packet = 3;
+
+  // optional - but required if type == DEBUG_EVENT
+  optional ACMDumpDebugEvent debug_event = 4;
+}
+
+message ACMDumpRTPPacket {
+  // Indicates if the packet is incoming or outgoing with respect to the user
+  // that is logging the data.
+  enum Direction {
+    UNKNOWN_DIRECTION = 0;
+    OUTGOING = 1;
+    INCOMING = 2;
+  }
+  enum PayloadType {
+    UNKNOWN_TYPE = 0;
+    AUDIO = 1;
+    VIDEO = 2;
+    RTX = 3;
+  }
+
+  // required
+  optional Direction direction = 1;
+
+  // required
+  optional PayloadType type = 2;
+
+  // required - Contains the whole RTP packet (header+payload).
+  optional bytes RTP_data = 3;
+}
+
+message ACMDumpDebugEvent {
+  // Indicates the type of the debug event.
+  // LOG_START and LOG_END indicate the start and end of the log respectively.
+  // AUDIO_PLAYOUT indicates a call to the PlayoutData10Ms() function in ACM.
+  enum EventType {
+    UNKNOWN_EVENT = 0;
+    LOG_START = 1;
+    LOG_END = 2;
+    AUDIO_PLAYOUT = 3;
+  }
+
+  // required
+  optional EventType type = 1;
+
+  // An optional message that can be used to store additional information about
+  // the debug event.
+  optional string message = 2;
+}