[UserTimingL3] {}, null, undefined passed to start treated as 0

According to the spec (https://w3c.github.io/user-timing/#measure-method),
UserTimingL3 API has the second argument being:
optional (DOMString or PerformanceMeasureOptions) startOrMeasureOptions

This indicates that the arg cannot distinguish between:
1. null
2. {}
3. undefined
4. { invalidDictProperty }

According to the spec:
3.1.3 measure() method...
 3. Compute start time as follows..
  4. Otherwise, let start time be 0.

When these indistinguishable values are passed, they should be
interpreted as start time being 0.

Bug: 953840

Change-Id: I052a7823d9ae8b27056f53f04a26fcc93421db75
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1691862
Commit-Queue: Liquan (Max) Gu <maxlg@chromium.org>
Reviewed-by: Nicolás Peña Moreno <npm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#675873}

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

@@ -86,6 +86,10 @@ const Performance::UnifiedClock* DefaultUnifiedClock() {
   return &unified_clock;
 }
 
+bool IsMeasureOptionsEmpty(const PerformanceMeasureOptions& options) {
+  return !options.hasDetail() && !options.hasEnd() && !options.hasStart();
+}
+
 }  // namespace
 
 using PerformanceObserverVector = HeapVector<Member<PerformanceObserver>>;
@@ -643,9 +647,12 @@ void Performance::clearMarks(const AtomicString& mark_name) {
 PerformanceMeasure* Performance::measure(ScriptState* script_state,
                                          const AtomicString& measure_name,
                                          ExceptionState& exception_state) {
+  // When |startOrOptions| is not provided, it's assumed to be an empty
+  // dictionary.
   return MeasureInternal(
       script_state, measure_name,
-      NativeValueTraits<StringOrPerformanceMeasureOptions>::NullValue(),
+      StringOrPerformanceMeasureOptions::FromPerformanceMeasureOptions(
+          PerformanceMeasureOptions::Create()),
       base::nullopt, exception_state);
 }
 
@@ -691,9 +698,13 @@ PerformanceMeasure* Performance::MeasureInternal(
     const StringOrPerformanceMeasureOptions& start_or_options,
     base::Optional<String> end,
     ExceptionState& exception_state) {
+  DCHECK(!start_or_options.IsNull());
   if (RuntimeEnabledFeatures::CustomUserTimingEnabled()) {
-    if (start_or_options.IsPerformanceMeasureOptions()) {
-      // measure("name", {}, *)
+    // An empty option is treated with no difference as null, undefined.
+    if (start_or_options.IsPerformanceMeasureOptions() &&
+        !IsMeasureOptionsEmpty(
+            *start_or_options.GetAsPerformanceMeasureOptions())) {
+      // measure("name", { start, end }, *)
       if (end) {
         exception_state.ThrowTypeError(
             "If a PerformanceMeasureOptions object was passed, |end| must be "
@@ -712,7 +723,8 @@ PerformanceMeasure* Performance::MeasureInternal(
         converted_start =
             StringOrDouble::FromString(start_or_options.GetAsString());
       } else {
-        DCHECK(start_or_options.IsNull());
+        DCHECK(start_or_options.IsNull() ||
+               start_or_options.IsPerformanceMeasureOptions());
         converted_start = NativeValueTraits<StringOrDouble>::NullValue();
       }
       // We let |end| behave the same whether it's empty, undefined or null in
@@ -729,13 +741,12 @@ PerformanceMeasure* Performance::MeasureInternal(
     // string 'null'.
     StringOrDouble converted_start;
     if (start_or_options.IsPerformanceMeasureOptions()) {
-      converted_start = StringOrDouble::FromString("[object Object]");
-    } else if (start_or_options.IsString()) {
+      converted_start = NativeValueTraits<StringOrDouble>::NullValue();
+    } else {
+      // |start_or_options| is not nullable.
+      DCHECK(start_or_options.IsString());
       converted_start =
           StringOrDouble::FromString(start_or_options.GetAsString());
-    } else {
-      DCHECK(start_or_options.IsNull());
-      DCHECK(converted_start.IsNull());
     }
 
     MeasureWithDetail(script_state, measure_name, converted_start,

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

@@ -73,7 +73,7 @@ interface Performance : EventTarget {
     // * L2 API returns null but this is a bug: crbug.com/914441.
     // * L3 API returns the created entry.
     // https://w3c.github.io/user-timing/#extensions-performance-interface
-    [MeasureAs=UserTiming, CallWith=ScriptState, RaisesException] PerformanceMeasure? measure(DOMString measureName, optional (DOMString or PerformanceMeasureOptions)? startOrOptions, optional DOMString end);
+    [MeasureAs=UserTiming, CallWith=ScriptState, RaisesException] PerformanceMeasure? measure(DOMString measureName, optional (DOMString or PerformanceMeasureOptions) startOrOptions, optional DOMString end);
     [MeasureAs=UserTiming] void clearMeasures(optional DOMString measureName = null);
 
     // TODO(foolip): There is no spec for the Memory Info API, see blink-dev:

third_party/blink/web_tests/external/wpt/user-timing/measure-with-dict.html

@@ -34,7 +34,11 @@
         { entryType: "measure", name: "measure14", detail: null, startTime: timeStamp3, duration: timeStamp1 - timeStamp3 },
         { entryType: "measure", name: "measure15", detail: null, startTime: timeStamp1, duration: timeStamp2 - timeStamp1 },
         { entryType: "measure", name: "measure16", detail: null, startTime: timeStamp1 },
-        { entryType: "measure", name: "measure17", detail: { customInfo: 159 }, startTime: timeStamp3, duration: timeStamp2 - timeStamp3 }];
+        { entryType: "measure", name: "measure17", detail: { customInfo: 159 }, startTime: timeStamp3, duration: timeStamp2 - timeStamp3 },
+        { entryType: "measure", name: "measure18", detail: null, startTime: 0 },
+        { entryType: "measure", name: "measure19", detail: null, startTime: 0 },
+        { entryType: "measure", name: "measure20", detail: null, startTime: 0 },
+        { entryType: "measure", name: "measure21", detail: null, startTime: 0 }];
     const observer = new PerformanceObserver(
         t.step_func(function (entryList, obs) {
           measureEntries =
@@ -81,19 +85,21 @@
         self.performance.measure("measure16", { start: 'mark1', end: undefined, detail: null }));
     returnedEntries.push(
         self.performance.measure("measure17", { start: timeStamp3, end: 'mark2', detail: { customInfo: 159 }}));
+    // {}, null, undefined, invalid-dict passed to startOrOptions are interpreted as start time being 0.
+    returnedEntries.push(self.performance.measure("measure18", {}, 'mark1'));
+    returnedEntries.push(self.performance.measure("measure19", null, 'mark1'));
+    returnedEntries.push(self.performance.measure("measure20", undefined, 'mark1'));
+    returnedEntries.push(self.performance.measure("measure21", { invalidDict:1 }, 'mark1'));
     checkEntries(returnedEntries, expectedEntries);
   }, "measure entries' detail and start/end are customizable");
 
-  test(function () {
+  test(function() {
     this.add_cleanup(cleanupPerformanceTimeline);
     assert_throws(new TypeError(), function() {
-      self.performance.measure("wrongUsage1", {}, 12);
+      self.performance.measure("wrongUsage2", {'start': 2}, 12);
     }, "measure should throw a TypeError when passed an options object and an end time");
     assert_throws(new TypeError(), function() {
-      self.performance.measure("wrongUsage2", {'startTime': 2}, 12);
-    }, "measure should throw a TypeError when passed an options object and an end time");
-    assert_throws(new TypeError(), function() {
-      self.performance.measure("wrongUsage3", {'startTime': 2}, 'mark1');
+      self.performance.measure("wrongUsage3", {'start': 2}, 'mark1');
     }, "measure should throw a TypeError when passed an options object and an end mark");
   }, "measure should throw a TypeError when passed an invalid argument combination");
 </script>

third_party/blink/web_tests/virtual/user-timing-l2/external/wpt/user-timing/mark-measure-return-objects-expected.txt

 This is a testharness.js-based test.
 FAIL L3: performance.measure(name) should return an entry. assert_true: expected true got false
-FAIL L3: performance.measure(name, param1) should return an entry. Failed to execute 'measure' on 'Performance': The mark '[object Object]' does not exist.
+FAIL L3: performance.measure(name, param1) should return an entry. assert_true: expected true got false
 FAIL L3: performance.measure(name, param1, param2) should return an entry. assert_true: expected true got false
 FAIL L3: performance.mark(name) should return an entry. assert_true: expected true got false
 FAIL L3: performance.mark(name, param) should return an entry. assert_true: expected true got false

third_party/blink/web_tests/virtual/user-timing-l2/external/wpt/user-timing/measure-with-dict-expected.txt

 This is a testharness.js-based test.
-FAIL measure entries' detail and start/end are customizable Failed to execute 'measure' on 'Performance': The mark '[object Object]' does not exist.
+FAIL measure entries' detail and start/end are customizable Cannot read property 'name' of null
 FAIL measure should throw a TypeError when passed an invalid argument combination assert_throws: measure should throw a TypeError when passed an options object and an end time function "function() {
-      self.performance.measure("wrongUsage1", {}, 12);
-    }" threw object "SyntaxError: Failed to execute 'measure' on 'Performance': The mark '[object Object]' does not exist." ("SyntaxError") expected object "TypeError" ("TypeError")
+      self.performance.measure("wrongUsage2", {'start': 2}, 12);
+    }" threw object "SyntaxError: Failed to execute 'measure' on 'Performance': The mark '12' does not exist." ("SyntaxError") expected object "TypeError" ("TypeError")
 Harness: the test ran to completion.
 

third_party/blink/web_tests/virtual/user-timing-l2/external/wpt/user-timing/structured-serialize-detail-expected.txt

@@ -5,12 +5,12 @@ FAIL When accessing detail from a mark entry and the detail is not provided, jus
 FAIL Mark: Throw an exception when the detail property cannot be structured-serialized. assert_throws: Trying to structured-serialize a Symbol. function "()=>{
       new PerformanceMark("A", { detail });
     }" did not throw
-FAIL The detail property in the measure method should be structured-clone. Failed to execute 'measure' on 'Performance': The mark '[object Object]' does not exist.
-FAIL The detail property in the measure method should be the same reference. Failed to execute 'measure' on 'Performance': The mark '[object Object]' does not exist.
+FAIL The detail property in the measure method should be structured-clone. Cannot read property 'detail' of null
+FAIL The detail property in the measure method should be the same reference. Cannot read property 'detail' of null
 FAIL When accessing detail from a measure entry and the detail is not provided, just return a null value. Cannot read property 'detail' of null
 FAIL Measure: Throw an exception when the detail property cannot be structured-serialized. assert_throws: Trying to structured-serialize a Symbol. function "()=>{
       performance.measure("A", { detail });
-    }" threw object "SyntaxError: Failed to execute 'measure' on 'Performance': The mark '[object Object]' does not exist." that is not a DOMException DataCloneError: property "code" is equal to 12, expected 25
+    }" did not throw
 FAIL The detail object is cloned when passed to mark API. Cannot read property 'detail' of null
 Harness: the test ran to completion.