Tracing V2 prototype [NOT FOR REVIEW]

base/BUILD.gn

Index: base/BUILD.gn
diff --git a/base/BUILD.gn b/base/BUILD.gn
index 56266feccb94502d580f9517991cf8105d019b49..df9ce8a68c5b436312119cdfe3f88493fd222e62 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -924,6 +924,16 @@ component("base") {
     "trace_event/trace_sampling_thread.h",
     "trace_event/tracing_agent.cc",
     "trace_event/tracing_agent.h",
+    "trace_event/v2/append_only_proto_message.cc",
+    "trace_event/v2/append_only_proto_message.h",
+    "trace_event/v2/proto_utils.cc",
+    "trace_event/v2/proto_utils.h",
+    "trace_event/v2/ring_buffer.cc",
+    "trace_event/v2/ring_buffer.h",
+    "trace_event/v2/scattered_buffer.h",
+    "trace_event/v2/scattered_buffer.cc",
+    "trace_event/v2/trace_event.h",
+    "trace_event/v2/trace_event.cc",
     "trace_event/winheap_dump_provider_win.cc",
     "trace_event/winheap_dump_provider_win.h",
     "tracked_objects.cc",
@@ -1009,6 +1019,12 @@ component("base") {
     "//third_party/modp_b64",
   ]
 
+  if (!is_nacl) {
+    deps += [
+      ":tracing_protos",
+    ]
+  }
+
   public_deps = [
     ":base_paths",
     ":base_static",
@@ -1676,6 +1692,11 @@ bundle_data("base_unittests_bundle_data") {
   ]
 }
 
+executable("tracing_perftests") {
+  sources = [ "trace_event/v2/append_only_proto_message_perftest.cc" ]
+  deps = [ ":base" ]
+}
+
 test("base_unittests") {
   sources = [
     "allocator/tcmalloc_unittest.cc",
@@ -1896,6 +1917,7 @@ test("base_unittests") {
     "timer/mock_timer_unittest.cc",
     "timer/timer_unittest.cc",
     "tools_sanity_unittest.cc",
+    "trace_event/v2/append_only_proto_message_unittest.cc",
     "trace_event/blame_context_unittest.cc",
     "trace_event/heap_profiler_allocation_context_tracker_unittest.cc",
     "trace_event/heap_profiler_allocation_register_unittest.cc",
@@ -2368,3 +2390,30 @@ if (is_android) {
         [ "test/android/java/src/org/chromium/base/ContentUriTestUtils.java" ]
   }
 }
+
+action("tracing_protos") {
+  script = "trace_event/v2/tracing_protoc.py"
+  gen_dir = "$target_gen_dir/trace_event/common/proto"
+
+  deps = [ "//third_party/protobuf:protoc" ]
+  public_configs = [ "//third_party/protobuf:using_proto" ]  # for gen/ include
+
+  inputs = [
+    "trace_event/common/proto/event.proto",
+    "trace_event/common/proto/events_chunk.proto",
+    "trace_event/common/proto/event_args_simple.proto",
+    "trace_event/common/proto/event_args_test.proto"
+  ]
+  outputs = [
+    "$gen_dir/event.pb.h",
+    "$gen_dir/events_chunk.pb.h",
+    "$gen_dir/event_args_simple.pb.h",
+  ]
+
+  args = [
+    "--protoc=" + rebase_path("$root_out_dir/protoc", root_build_dir),
+    "--proto-in-dir=" + rebase_path("trace_event/common/proto", root_build_dir),
+    "--proto-out-dir=" + rebase_path("$gen_dir", root_build_dir),
+  ]
+  args += rebase_path(inputs, root_build_dir)
+}