DevTools: Reenable tracing-based JS profile.

It was accidentally disabled by r627247.

Change-Id: I847a40d3350cad56c4967af850a93e854ae15614
Reviewed-on: https://chromium-review.googlesource.com/c/1457007
Auto-Submit: Alexei Filippov <alph@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
Commit-Queue: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Pavel Feldman <pfeldman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#629791}

third_party/blink/renderer/devtools/front_end/timeline/TimelineController.js

@@ -65,7 +65,7 @@ Timeline.TimelineController = class {
 
     if (Runtime.experiments.isEnabled('timelineV8RuntimeCallStats') && options.enableJSSampling)
       categoriesArray.push(disabledByDefault('v8.runtime_stats_sampling'));
-    if (Runtime.queryParam('timelineTracingJSProfile') && options.enableJSSampling) {
+    if (!Runtime.queryParam('timelineTracingJSProfileDisabled') && options.enableJSSampling) {
       categoriesArray.push(disabledByDefault('v8.cpu_profiler'));
       if (Common.moduleSetting('highResolutionCpuProfiling').get())
         categoriesArray.push(disabledByDefault('v8.cpu_profiler.hires'));
@@ -175,7 +175,7 @@ Timeline.TimelineController = class {
    */
   async _startRecordingWithCategories(categories, enableJSSampling) {
     SDK.targetManager.suspendAllTargets();
-    if (enableJSSampling && !Runtime.queryParam('timelineTracingJSProfile'))
+    if (enableJSSampling && Runtime.queryParam('timelineTracingJSProfileDisabled'))
       await this._startProfilingOnAllModels();
     if (!this._tracingManager)
       return;

third_party/blink/web_tests/http/tests/devtools/tracing/timeline-js/timeline-has-cpu-profile-events-expected.txt

+Test the Timeline instrumentation contains Profile event.
+

third_party/blink/web_tests/http/tests/devtools/tracing/timeline-js/timeline-has-cpu-profile-events.js

+// Copyright 2019 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.
+
+(async function() {
+  TestRunner.addResult(`Test the Timeline instrumentation contains Profile event.`);
+  await TestRunner.loadModule('performance_test_runner');
+  await TestRunner.showPanel('timeline');
+
+  await PerformanceTestRunner.evaluateWithTimeline('42');
+  const profileEvent = PerformanceTestRunner.findTimelineEvent(TimelineModel.TimelineModel.RecordType.Profile);
+  TestRunner.check(profileEvent, 'Profile trace event not found.');
+
+  TestRunner.completeTest();
+})();