Add out-of-process memory logging stream parsing.

chrome/common/profiling/memlog_stream.h

Index: chrome/common/profiling/memlog_stream.h
diff --git a/chrome/common/profiling/memlog_stream.h b/chrome/common/profiling/memlog_stream.h
index 7a9e98d2c4a700473ceabd9632777e12a823586d..fa6810bf3c661f79b80d8a755f4544a18d2966aa 100644
--- a/chrome/common/profiling/memlog_stream.h
+++ b/chrome/common/profiling/memlog_stream.h
@@ -5,10 +5,45 @@
 #ifndef CHROME_COMMON_PROFILING_MEMLOG_STREAM_H_
 #define CHROME_COMMON_PROFILING_MEMLOG_STREAM_H_
 
+#include <stdint.h>
+
 #include "build/build_config.h"
 
 namespace profiling {
 
+static const uint32_t kStreamSignature = 0xF6103B71;
+static const uint32_t kStreamVersion = 1;
+
+static const uint32_t kAllocPacketType = 0xA1A1A1A1;
+static const uint32_t kFreePacketType = 0xFEFEFEFE;
+
+#pragma pack(push, 1)
+struct StreamHeader {
+  uint32_t signature;  // kStreamSignature
+  uint32_t version;
+
+  char proctype[16];

[Boris Vidolov, 2017/06/16 21:16:46]

What will this be?

[brettw, 2017/06/16 23:58:13]

I meant to delete that but did it in the next path instead. I deleted it now.

+};
+
+struct AllocPacket {
+  uint32_t op;  // = kAllocPacketType
+
+  uint64_t time;
+  uint64_t address;
+  uint64_t size;
+
+  uint32_t stack_len;
+  // Immediately followed by |stack_len| more addresses.
+};
+
+struct FreePacket {
+  uint32_t op;  // = kFreePacketType
+
+  uint64_t time;
+  uint64_t address;

[Boris Vidolov, 2017/06/16 21:16:45]

No stack trace here?

[brettw, 2017/06/16 23:58:13]

No, I didn't hook up free stack traces. It's easy to add if we need it.

+};
+#pragma pack(pop)
+
 #if defined(OS_WIN)
 // Prefix for pipe name for communicating between chrome processes and the
 // memlog process. The pipe ID is appended to this to get the pipe name.