[user-timing] Not throw when known names are used as marks in a worker

User timing's mark() was throwing when called with a well-known name
inside a worker. According to the spec and tests, it should only throw
in such a case on the main thread.
This CL aligns our implementation with the spec.

Change-Id: Idb43038105301a41cd7d2c676ca1fc401a684058
Reviewed-on: https://chromium-review.googlesource.com/c/1373830Reviewed-by: Nicolás Peña Moreno <npm@chromium.org>
Commit-Queue: Yoav Weiss <yoavweiss@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615946}

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

@@ -133,7 +133,11 @@ PerformanceMark* UserTiming::MarkInternal(ScriptState* script_state,
                                           const DOMHighResTimeStamp& start_time,
                                           const ScriptValue& detail,
                                           ExceptionState& exception_state) {
-  if (GetRestrictedKeyMap().Contains(mark_name)) {
+  DCHECK(performance_);
+  bool is_worker_global_scope =
+      performance_->GetExecutionContext() &&
+      performance_->GetExecutionContext()->IsWorkerGlobalScope();
+  if (!is_worker_global_scope && GetRestrictedKeyMap().Contains(mark_name)) {
     exception_state.ThrowDOMException(
         DOMExceptionCode::kSyntaxError,
         "'" + mark_name +

third_party/blink/web_tests/TestExpectations

@@ -4329,7 +4329,6 @@ crbug.com/709227 external/wpt/offscreen-canvas/the-offscreen-canvas/size.attribu
 crbug.com/709227 external/wpt/offscreen-canvas/the-offscreen-canvas/size.attributes.parse.onlyspace.worker.html [ Failure ]
 crbug.com/709227 external/wpt/offscreen-canvas/the-offscreen-canvas/size.attributes.parse.percent.worker.html [ Failure ]
 crbug.com/709227 external/wpt/offscreen-canvas/the-offscreen-canvas/size.attributes.parse.trailingjunk.worker.html [ Failure ]
-crbug.com/709227 external/wpt/user-timing/invoke_with_timing_attributes.worker.html [ Failure ]
 
 # Crashes
 crbug.com/709227 external/wpt/offscreen-canvas/fill-and-stroke-styles/2d.pattern.basic.nocontext.worker.html [ Crash Pass ]