Remove LongTaskV2 flag

We do not intend to ship this feature, so remove the flag and some of
the associated code. A followup CL will remove SubTaskAttributions and
code used to compute them.

Bug: 738493
Change-Id: I6b036e5d308bf8e555f5d5c76874e12458a028c2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1853124Reviewed-by: Tom McKee <tommckee@chromium.org>
Reviewed-by: Steve Kobes <skobes@chromium.org>
Commit-Queue: Nicolás Peña Moreno <npm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#706448}

third_party/blink/renderer/core/timing/performance_long_task_timing.cc

@@ -23,21 +23,10 @@ PerformanceLongTaskTiming::PerformanceLongTaskTiming(
     const SubTaskAttribution::EntriesVector& sub_task_attributions)
     : PerformanceEntry(name, start_time, end_time) {
   // Only one possible container type exists currently: "iframe".
-  if (RuntimeEnabledFeatures::LongTaskV2Enabled()) {
-    for (auto&& it : sub_task_attributions) {
-      TaskAttributionTiming* attribution_entry = TaskAttributionTiming::Create(
-          it->subTaskName(), "iframe", culprit_frame_src, culprit_frame_id,
-          culprit_frame_name, it->highResStartTime(),
-          it->highResStartTime() + it->highResDuration(), it->scriptURL());
-      attribution_.push_back(*attribution_entry);
-    }
-  } else {
-    // Only one possible task type exists currently: "script".
-    TaskAttributionTiming* attribution_entry =
-        TaskAttributionTiming::Create("unknown", "iframe", culprit_frame_src,
-                                      culprit_frame_id, culprit_frame_name);
-    attribution_.push_back(*attribution_entry);
-  }
+  TaskAttributionTiming* attribution_entry =
+      TaskAttributionTiming::Create("unknown", "iframe", culprit_frame_src,
+                                    culprit_frame_id, culprit_frame_name);
+  attribution_.push_back(*attribution_entry);
 }
 
 PerformanceLongTaskTiming::~PerformanceLongTaskTiming() = default;

third_party/blink/renderer/core/timing/task_attribution_timing.cc

@@ -14,16 +14,12 @@ TaskAttributionTiming::TaskAttributionTiming(const AtomicString& name,
                                              const String& container_type,
                                              const String& container_src,
                                              const String& container_id,
-                                             const String& container_name,
-                                             double start_time,
-                                             double finish_time,
-                                             const String& script_url)
-    : PerformanceEntry(name, start_time, finish_time),
+                                             const String& container_name)
+    : PerformanceEntry(name, 0.0, 0.0),
       container_type_(container_type),
       container_src_(container_src),
       container_id_(container_id),
-      container_name_(container_name),
-      script_url_(script_url) {}
+      container_name_(container_name) {}
 
 TaskAttributionTiming::~TaskAttributionTiming() = default;
 
@@ -35,10 +31,6 @@ PerformanceEntryType TaskAttributionTiming::EntryTypeEnum() const {
   return PerformanceEntry::EntryType::kTaskAttribution;
 }
 
-String TaskAttributionTiming::scriptURL() const {
-  return script_url_;
-}
-
 String TaskAttributionTiming::containerType() const {
   return container_type_;
 }

third_party/blink/renderer/core/timing/task_attribution_timing.h

@@ -16,29 +16,13 @@ class TaskAttributionTiming final : public PerformanceEntry {
   DEFINE_WRAPPERTYPEINFO();
 
  public:
-  // Used when the LongTaskV2 flag is enabled.
-  static TaskAttributionTiming* Create(const AtomicString& type,
-                                       const String& container_type,
-                                       const String& container_src,
-                                       const String& container_id,
-                                       const String& container_name,
-                                       double start_time,
-                                       double finish_time,
-                                       const String& script_url) {
-    return MakeGarbageCollected<TaskAttributionTiming>(
-        type, container_type, container_src, container_id, container_name,
-        start_time, finish_time, script_url);
-  }
-
-  // Used when the LongTaskV2 flag is disabled.
   static TaskAttributionTiming* Create(const AtomicString& type,
                                        const String& container_type,
                                        const String& container_src,
                                        const String& container_id,
                                        const String& container_name) {
     return MakeGarbageCollected<TaskAttributionTiming>(
-        type, container_type, container_src, container_id, container_name, 0.0,
-        0.0, g_empty_string);
+        type, container_type, container_src, container_id, container_name);
   }
 
   AtomicString entryType() const override;
@@ -48,7 +32,6 @@ class TaskAttributionTiming final : public PerformanceEntry {
   String containerSrc() const;
   String containerId() const;
   String containerName() const;
-  String scriptURL() const;
 
   void Trace(blink::Visitor*) override;
 
@@ -56,10 +39,7 @@ class TaskAttributionTiming final : public PerformanceEntry {
                         const String& container_type,
                         const String& container_src,
                         const String& container_id,
-                        const String& container_name,
-                        double start_time,
-                        double finish_time,
-                        const String& script_url);
+                        const String& container_name);
   ~TaskAttributionTiming() override;
 
  private:
@@ -69,7 +49,6 @@ class TaskAttributionTiming final : public PerformanceEntry {
   String container_src_;
   String container_id_;
   String container_name_;
-  String script_url_;
 };
 
 }  // namespace blink

third_party/blink/renderer/core/timing/task_attribution_timing.idl

@@ -5,7 +5,6 @@
 // https://w3c.github.io/longtasks/#sec-TaskAttributionTiming
 [Exposed=Window]
 interface TaskAttributionTiming : PerformanceEntry {
-    [RuntimeEnabled=LongTaskV2] readonly attribute DOMString scriptURL;
     readonly attribute DOMString containerType;
     readonly attribute DOMString containerSrc;
     readonly attribute DOMString containerId;

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -911,9 +911,6 @@
       name: "LinkSystemColors",
       status: "stable",
     },
-    {
-      name: "LongTaskV2",
-    },
     {
       name:"ManualSlotting",
       status:"experimental",

third_party/blink/web_tests/TestExpectations

@@ -2447,10 +2447,6 @@ crbug.com/863896 http/tests/permissions/test-query.html [ Timeout ]
 
 crbug.com/876485 fast/performance/performance-measure-null-exception.html [ Failure ]
 
-# These tests requires enabling the flag LongTaskV2 in a virtual test suite.
-crbug.com/738493 http/tests/performance-timing/longtask-v2/longtask-v8compile.html [ Skip ]
-crbug.com/738493 http/tests/performance-timing/longtask-v2/longtask-executescript.html [ Skip ]
-
 crbug.com/713587 external/wpt/css/css-ui/caret-color-006.html [ Skip ]
 
 # Automatically-added expectations for CSS tests which are temporarily

third_party/blink/web_tests/VirtualTestSuites

@@ -486,11 +486,6 @@
     "base": "receiver",
     "args": ["--force-presentation-receiver-for-testing"]
   },
-  {
-    "prefix": "longtask-v2",
-    "base": "http/tests/performance-timing/longtask-v2",
-    "args": ["--enable-blink-features=LongTaskV2"]
-  },
   {
     "prefix": "paint-timing",
     "base": "external/wpt/paint-timing",

third_party/blink/web_tests/http/tests/performance-timing/longtask-v2/longtask-executescript.html

-\<!DOCTYPE HTML>
-<meta charset=utf-8>
-<title>LongTask Timing: validate the long task attributes for execute-script</title>
-<body>
-
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-
-<h1>Long Task Attributes for Execute Script</h1>
-<div id="log"></div>
-<script>
-  async_test(function (t) {
-    if (typeof PerformanceLongTaskTiming === 'undefined') {
-        assert_unreached("Longtasks are not supported.");
-        t.done();
-    }
-    const scriptURL = 'longtask-executescript.html';
-    const observer = new PerformanceObserver(
-      t.step_func(function (entryList) {
-        const longtaskEntries = entryList.getEntries().filter((e) => {
-          return e.attribution.find((a) => {
-            return a.scriptURL.includes(scriptURL);
-          });
-        });
-        if (longtaskEntries.length === 0) {
-          return;
-        }
-        assert_equals(longtaskEntries.length, 1);
-        const longtask = longtaskEntries[0];
-        assert_equals(longtask.entryType, 'longtask');
-        assert_equals(longtask.name, 'self');
-        assert_greater_than(longtask.duration, 50);
-        assert_greater_than_equal(longtask.startTime, 0);
-        const currentTime = performance.now();
-        assert_less_than_equal(longtask.startTime, currentTime);
-
-        const runAttribution = longtask.attribution.filter(function(it) {
-          return it.name === 'script-run' &&
-              it.scriptURL.includes(scriptURL);
-        });
-        assert_equals(runAttribution.length, 1);
-        const it = runAttribution[0];
-        assert_greater_than(it.duration, 51);
-        assert_greater_than(it.startTime, 0);
-        assert_equals(it.entryType, 'taskattribution');
-        assert_equals(it.containerType, 'iframe');
-        assert_equals(it.containerId, '');
-        assert_equals(it.containerName, '');
-        assert_equals(it.containerSrc, '');
-        assert_true(it.scriptURL.includes(scriptURL));
-        observer.disconnect();
-        t.done();
-      })
-    );
-    observer.observe({entryTypes: ['longtask']});
-
-    /* Generate a slow task. */
-    const begin = window.performance.now();
-    while (window.performance.now() < begin + 51);
-
-}, 'Performance longtask entries with execute-script attribute are observable.');
-</script>
-
-</body>

third_party/blink/web_tests/http/tests/performance-timing/longtask-v2/longtask-v8compile.html

-<!DOCTYPE HTML>
-<meta charset=utf-8>
-<title>LongTask Timing: validate the long task attributes for script-compile</title>
-<body>
-
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-
-<h1>Long Task Attributes for Script-compile</h1>
-<div id="log"></div>
-<script>
-  async_test(function (t) {
-    if (typeof PerformanceLongTaskTiming === 'undefined') {
-        assert_unreached("Longtasks are not supported.");
-        t.done();
-    }
-    const scriptURL = 'resources/makelongtask.js';
-    const lineColumn = '(0, 0)';
-    const observer = new PerformanceObserver(
-      t.step_func(function(entryList) {
-        const longtaskEntries = entryList.getEntries().filter((e) => {
-          return e.attribution.find((a) => {
-            return a.scriptURL.includes(scriptURL);
-          });
-        });
-        if (longtaskEntries.length === 0) {
-          return;
-        }
-        assert_equals(longtaskEntries.length, 1);
-        const longtask = longtaskEntries[0];
-        assert_equals(longtask.entryType, 'longtask');
-        assert_equals(longtask.name, 'self');
-        assert_greater_than(longtask.duration, 50);
-        assert_greater_than_equal(longtask.startTime, 0);
-        const currentTime = performance.now();
-        assert_less_than_equal(longtask.startTime, currentTime);
-
-        const compileAttribution = longtask.attribution.filter((it) => {
-          return it.name === 'script-compile' &&
-              it.scriptURL.includes(scriptURL);
-        });
-        assert_equals(compileAttribution.length, 1);
-        const it = compileAttribution[0];
-        assert_greater_than(it.startTime, 0);
-        assert_equals(it.entryType, 'taskattribution');
-        assert_equals(it.containerType, 'iframe');
-        assert_equals(it.containerId, '');
-        assert_equals(it.containerName, '');
-        assert_equals(it.containerSrc, '');
-        assert_true(it.scriptURL.includes(scriptURL + lineColumn));
-        observer.disconnect();
-        t.done();
-      })
-    );
-    observer.observe({entryTypes: ['longtask']});
-
-    internals.BypassLongCompileThresholdOnce();
-
-    var iframe=document.createElement('Script');
-    iframe.src = "resources/makelongtask.js";
-    document.body.appendChild(iframe);
-
-}, 'Performance longtask entries with script-compile attribute are observable.');
-</script>
-
-</body>
\ No newline at end of file

third_party/blink/web_tests/http/tests/performance-timing/longtask-v2/resources/makelongtask.js

-/* Generate a slow task. */
-const begin = window.performance.now();
-while (window.performance.now() < begin + 51);
\ No newline at end of file

third_party/blink/web_tests/virtual/longtask-v2/http/tests/performance-timing/longtask-v2/README.txt

-This directory contains the test cases for longtask API v2. For now, the
-longtask API V2 are still working in progress and not ready to be web-exposed
- yet. Some of them, if appropriate to be web-platform-tests, will be upstreamed
-to web-platform-tests after longtask v2 are fully implemented.
-
-The test cases in this directory requires enabling of runtime feature flag
-LongTaskV2.