[devtools] Remove devtools.timeline.async category.

Together with removing the frontend code in crrev.com/c/2617780, remove
the code emitting the old-style flow events for devtools and remove the
category.

R=caseq@chromium.org,eseckler@chromium.org
CC=yangguo@chromium.org
BUG=1164298

Change-Id: I929c09d8aef5fb07ff64b0aa5960126111f433ae
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2617939Reviewed-by: Eric Seckler <eseckler@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Commit-Queue: Alexander Timin <altimin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#842137}

base/trace_event/builtin_categories.h

@@ -66,7 +66,6 @@
   X("device")                                                            \
   X("devtools")                                                          \
   X("devtools.timeline")                                                 \
-  X("devtools.timeline.async")                                           \
   X("disk_cache")                                                        \
   X("download")                                                          \
   X("download_service")                                                  \

third_party/blink/renderer/core/probe/core_probes.cc

@@ -52,8 +52,6 @@ void* AsyncId(AsyncTaskId* task) {
 void AsyncTaskCanceled(v8::Isolate* isolate, AsyncTaskId* task) {
   if (ThreadDebugger* debugger = ThreadDebugger::From(isolate))
     debugger->AsyncTaskCanceled(AsyncId(task));
-  TRACE_EVENT_FLOW_END0("devtools.timeline.async", "AsyncTask",
-                        TRACE_ID_LOCAL(reinterpret_cast<uintptr_t>(task)));
 }
 
 }  // namespace
@@ -94,14 +92,6 @@ AsyncTask::AsyncTask(ExecutionContext* context,
                         ctx.event()->add_flow_ids(task->GetTraceId().value());
                       });
   }
-  if (recurring_) {
-    TRACE_EVENT_FLOW_STEP0("devtools.timeline.async", "AsyncTask",
-                           TRACE_ID_LOCAL(reinterpret_cast<uintptr_t>(task)),
-                           step ? step : "");
-  } else {
-    TRACE_EVENT_FLOW_END0("devtools.timeline.async", "AsyncTask",
-                          TRACE_ID_LOCAL(reinterpret_cast<uintptr_t>(task)));
-  }
   if (debugger_)
     debugger_->AsyncTaskStarted(AsyncId(task_));
 
@@ -127,9 +117,6 @@ AsyncTask::~AsyncTask() {
 void AsyncTaskScheduled(ExecutionContext* context,
                         const StringView& name,
                         AsyncTaskId* task) {
-  TRACE_EVENT_FLOW_BEGIN1("devtools.timeline.async", "AsyncTask",
-                          TRACE_ID_LOCAL(reinterpret_cast<uintptr_t>(task)),
-                          "data", inspector_async_task::Data(name));
   uint64_t trace_id = base::trace_event::GetNextGlobalTraceId();
   task->SetTraceId(trace_id);
   TRACE_EVENT("blink", "AsyncTask Scheduled", [&](perfetto::EventContext ctx) {