tracing v2: Introduce TraceBufferReader to read-back the trace buffer

components/tracing/core/string_interning.cc

Index: components/tracing/core/string_interning.cc
diff --git a/components/tracing/core/string_interning.cc b/components/tracing/core/string_interning.cc
new file mode 100644
index 0000000000000000000000000000000000000000..497bf74bcac1b6345ee12307dc25a4fdedf86c90
--- /dev/null
+++ b/components/tracing/core/string_interning.cc
@@ -0,0 +1,19 @@
+// Copyright 2016 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 "components/tracing/core/string_interning.h"
+
+namespace tracing {
+namespace v2 {
+
+// TODO(primiano): there is a possibile optimization here: if we somehow
+// guarantee that kInternedStringBase is always laid out before any other string
+// in the binary, we can minimize the ptr distance and hence reduce the number
+// of bytes required to VarInt-encode it. Very likely this can be done using
+// __attribute__((section(X))) on Linux or __attribute__((section("__TEXT,X")))
+// on OSX.

[kraynov, 2016/09/08 16:10:01]

Yep, maybe dynamic linker has some tricks as well.

[Primiano Tucci (use gerrit), 2016/09/13 14:40:24]

Acknowledged.

+const char kInternedStringBase[] = "Chrome Tracing v2";

[oystein (OOO til 10th of July), 2016/09/09 00:27:34]

supernit: just "Tracing v2", there's other embedders.

[Primiano Tucci (use gerrit), 2016/09/13 14:40:24]

Done.

+
+}  // namespace v2
+}  // namespace tracing