Worklet: Move common code of addModule from Main/ThreadedWorklet to Worklet

third_party/WebKit/Source/core/workers/Worklet.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 "core/workers/Worklet.h"
 
+#include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/DOMException.h"
 #include "core/dom/Document.h"
+#include "core/dom/TaskRunnerHelper.h"
 #include "core/frame/LocalFrame.h"
 #include "core/workers/WorkletGlobalScopeProxy.h"
 
 namespace blink {
 
 Worklet::Worklet(LocalFrame* frame)
-    : ContextLifecycleObserver(frame->GetDocument()), frame_(frame) {
+    : ContextLifecycleObserver(frame->GetDocument()) {
   DCHECK(IsMainThread());
 }
 
-void Worklet::ContextDestroyed(ExecutionContext*) {
+// Implementation of the first half of the "addModule(moduleURL, options)"
+// algorithm:
+// https://drafts.css-houdini.org/worklets/#dom-worklet-addmodule
+ScriptPromise Worklet::addModule(ScriptState* script_state,
+                                 const String& module_url) {
   DCHECK(IsMainThread());
-  frame_ = nullptr;
+  if (!GetExecutionContext()) {
+    return ScriptPromise::RejectWithDOMException(
+        script_state, DOMException::Create(kInvalidStateError,
+                                           "This frame is already detached"));
+  }
+
+  // Step 1: "Let promise be a new promise."
+  ScriptPromiseResolver* resolver = ScriptPromiseResolver::Create(script_state);
+  ScriptPromise promise = resolver->Promise();
+
+  // Step 2: "Let worklet be the current Worklet."
+  // |this| is the current Worklet.
+
+  // Step 3: "Let moduleURLRecord be the result of parsing the moduleURL
+  // argument relative to the relevant settings object of this."
+  KURL module_url_record = GetExecutionContext()->CompleteURL(module_url);
+
+  // Step 4: "If moduleURLRecord is failure, then reject promise with a
+  // "SyntaxError" DOMException and return promise."
+  if (!module_url_record.IsValid()) {
+    resolver->Reject(DOMException::Create(
+        kSyntaxError, "'" + module_url + "' is not a valid URL."));
+    return promise;
+  }
+
+  // Step 5: "Return promise, and then continue running this algorithm in
+  // parallel."
+  // |kUnspecedLoading| is used here because this is a part of script module
+  // loading.
+  TaskRunnerHelper::Get(TaskType::kUnspecedLoading, script_state)
+      ->PostTask(BLINK_FROM_HERE,
+                 WTF::Bind(&Worklet::FetchAndInvokeScript, WrapPersistent(this),
+                           module_url_record, WrapPersistent(resolver)));
+  return promise;
 }
 
 DEFINE_TRACE(Worklet) {
-  visitor->Trace(frame_);
   ContextLifecycleObserver::Trace(visitor);
 }
 
 }  // namespace blink