Use wrapper tracing for worklets.

third_party/WebKit/Source/modules/csspaint/PaintWorkletGlobalScope.cpp

 // Copyright 2016 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.
 
 #include "modules/csspaint/PaintWorkletGlobalScope.h"
 
 #include "bindings/core/v8/IDLTypes.h"
 #include "bindings/core/v8/NativeValueTraitsImpl.h"
 #include "bindings/core/v8/WorkerOrWorkletScriptController.h"
 #include "core/CSSPropertyNames.h"
@@ skipping 39 matching lines @@
                                    std::move(security_origin),
                                    isolate),
       pending_generator_registry_(pending_generator_registry) {}
 
 PaintWorkletGlobalScope::~PaintWorkletGlobalScope() {}
 
 void PaintWorkletGlobalScope::Dispose() {
   MainThreadDebugger::Instance()->ContextWillBeDestroyed(
       ScriptController()->GetScriptState());
 
-  // Explicitly clear the paint defininitions to break a reference cycle
-  // between them and this global scope.
-  paint_definitions_.clear();
-
   pending_generator_registry_ = nullptr;
   WorkletGlobalScope::Dispose();
 }
 
 void PaintWorkletGlobalScope::registerPaint(const String& name,
                                             const ScriptValue& ctor_value,
                                             ExceptionState& exception_state) {
   if (paint_definitions_.Contains(name)) {
     exception_state.ThrowDOMException(
         kNotSupportedError,
@@ skipping 117 matching lines @@
         "The 'paint' property on the prototype is not a function.");
     return;
   }
 
   v8::Local<v8::Function> paint = v8::Local<v8::Function>::Cast(paint_value);
 
   CSSPaintDefinition* definition = CSSPaintDefinition::Create(
       ScriptController()->GetScriptState(), constructor, paint,
       native_invalidation_properties, custom_invalidation_properties,
       input_argument_types, has_alpha);
-  paint_definitions_.Set(name, definition);
+  paint_definitions_.Set(
+      name, TraceWrapperMember<CSSPaintDefinition>(this, definition));
   pending_generator_registry_->SetDefinition(name, definition);
 }
 
 CSSPaintDefinition* PaintWorkletGlobalScope::FindDefinition(
     const String& name) {
   return paint_definitions_.at(name);
 }
 
 DEFINE_TRACE(PaintWorkletGlobalScope) {
   visitor->Trace(paint_definitions_);
   visitor->Trace(pending_generator_registry_);
   MainThreadWorkletGlobalScope::Trace(visitor);
 }
 
+DEFINE_TRACE_WRAPPERS(PaintWorkletGlobalScope) {
+  for (auto definition : paint_definitions_)
+    visitor->TraceWrappers(definition.value);
+  MainThreadWorkletGlobalScope::TraceWrappers(visitor);
+}
+
 }  // namespace blink