Worklet: Move loader client impl from ThreadedWorklet to ThreadedWorkletMessagingProxy

third_party/WebKit/Source/core/workers/ThreadedWorklet.cpp

 // Copyright 2017 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/ThreadedWorklet.h"
 
 #include "bindings/core/v8/ScriptSourceCode.h"
 #include "bindings/core/v8/V8BindingForCore.h"
 #include "core/dom/DOMException.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExceptionCode.h"
+#include "core/dom/TaskRunnerHelper.h"
 #include "core/frame/LocalFrame.h"
 #include "core/workers/WorkletGlobalScopeProxy.h"
+#include "core/workers/WorkletPendingTasks.h"
+#include "platform/WebTaskRunner.h"
 #include "platform/wtf/WTF.h"
 
 namespace blink {
 
 ThreadedWorklet::ThreadedWorklet(LocalFrame* frame) : Worklet(frame) {}
 
+// Implementation of the second half of the "addModule(moduleURL, options)"
+// algorithm:
+// https://drafts.css-houdini.org/worklets/#dom-worklet-addmodule
+// TODO(nhiroki): MainThreadWorklet::FetchAndInvokeScript will be moved to the
+// parent class (i.e., Worklet) and this function will be replaced with it.
+// (https://crbug.com/727194)
 void ThreadedWorklet::FetchAndInvokeScript(const KURL& module_url_record,
-                                           const WorkletOptions&,
+                                           const WorkletOptions& options,
                                            ScriptPromiseResolver* resolver) {
   DCHECK(IsMainThread());
   if (!GetExecutionContext())
     return;
 
   if (!IsInitialized())
     Initialize();
 
-  WorkletScriptLoader* script_loader = WorkletScriptLoader::Create(
-      ToDocument(GetExecutionContext())->Fetcher(), this);
-  loader_to_resolver_map_.Set(script_loader, resolver);
-  script_loader->FetchScript(module_url_record);
-}
+  // Step 6: "Let credentialOptions be the credentials member of options."
+  // TODO(nhiroki): Add tests for credentialOptions (https://crbug.com/710837).
+  WebURLRequest::FetchCredentialsMode credentials_mode =
+      ParseCredentialsOption(options.credentials());
 
-void ThreadedWorklet::NotifyWorkletScriptLoadingFinished(
-    WorkletScriptLoader* script_loader,
-    const ScriptSourceCode& source_code) {
-  DCHECK(IsMainThread());
-  ScriptPromiseResolver* resolver = loader_to_resolver_map_.at(script_loader);
-  loader_to_resolver_map_.erase(script_loader);
+  // Step 7: "Let outsideSettings be the relevant settings object of this."
+  // In the specification, outsideSettings is used for posting a task to the
+  // document's responsible event loop. In our implementation, we use the
+  // document's UnspecedLoading task runner as that is what we commonly use for
+  // module loading.
+  RefPtr<WebTaskRunner> outside_settings_task_runner =
+      TaskRunnerHelper::Get(TaskType::kUnspecedLoading, GetExecutionContext());
 
-  if (!script_loader->WasScriptLoadSuccessful()) {
-    resolver->Reject(DOMException::Create(kNetworkError));
-    return;
-  }
+  // Step 8: "Let moduleResponsesMap be worklet's module responses map."
+  // TODO(nhiroki): Implement moduleResponsesMap (https://crbug.com/627945).
 
-  GetWorkletGlobalScopeProxy()->EvaluateScript(source_code);
-  resolver->Resolve();
+  // Step 9: "Let workletGlobalScopeType be worklet's worklet global scope
+  // type."
+  // workletGlobalScopeType is encoded into the class name (e.g., PaintWorklet).
+
+  // Step 10: "If the worklet's WorkletGlobalScopes is empty, run the following
+  // steps:"
+  //   10.1: "Create a WorkletGlobalScope given workletGlobalScopeType,
+  //          moduleResponsesMap, and outsideSettings."
+  //   10.2: "Add the WorkletGlobalScope to worklet's WorkletGlobalScopes."
+  // "Depending on the type of worklet the user agent may create additional
+  // WorkletGlobalScopes at this time."
+  // TODO(nhiroki): These steps will be supported after MainThreadWorklet and
+  // ThreadedWorklet are merged into Worklet (https://crbug.com/727194)
+
+  // Step 11: "Let pendingTaskStruct be a new pending tasks struct with counter
+  // initialized to the length of worklet's WorkletGlobalScopes."
+  const int kNumberOfGlobalScopes = 1;
+  WorkletPendingTasks* pending_tasks =
+      new WorkletPendingTasks(kNumberOfGlobalScopes, resolver);
+
+  // Step 12: "For each workletGlobalScope in the worklet's
+  // WorkletGlobalScopes, queue a task on the workletGlobalScope to fetch and
+  // invoke a worklet script given workletGlobalScope, moduleURLRecord,
+  // moduleResponsesMap, credentialOptions, outsideSettings, pendingTaskStruct,
+  // and promise."
+  // TODO(nhiroki): Queue a task instead of executing this here.
+  GetWorkletGlobalScopeProxy()->FetchAndInvokeScript(
+      module_url_record, credentials_mode,
+      std::move(outside_settings_task_runner), pending_tasks);
 }
 
 void ThreadedWorklet::ContextDestroyed(ExecutionContext* execution_context) {
   DCHECK(IsMainThread());
-  for (const auto& script_loader : loader_to_resolver_map_.Keys())
-    script_loader->Cancel();
-  loader_to_resolver_map_.clear();
   if (IsInitialized())
     GetWorkletGlobalScopeProxy()->TerminateWorkletGlobalScope();
 }
 
 DEFINE_TRACE(ThreadedWorklet) {
-  visitor->Trace(loader_to_resolver_map_);
   Worklet::Trace(visitor);
 }
 
 }  // namespace blink