[WIP] Worklet: Merge MainThreadWorklet and ThreadedWorklet into Worklet

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

Index: third_party/WebKit/Source/core/workers/Worklet.cpp
diff --git a/third_party/WebKit/Source/core/workers/Worklet.cpp b/third_party/WebKit/Source/core/workers/Worklet.cpp
index 6620d822b7d92d4b754b6a80fd0832aaa5d7423f..fd85146ec383ab1de10938df39583ff0bb8202a2 100644
--- a/third_party/WebKit/Source/core/workers/Worklet.cpp
+++ b/third_party/WebKit/Source/core/workers/Worklet.cpp
@@ -10,9 +10,28 @@
 #include "core/dom/TaskRunnerHelper.h"
 #include "core/frame/LocalFrame.h"
 #include "core/workers/WorkletGlobalScopeProxy.h"
+#include "core/workers/WorkletPendingTasks.h"
+#include "platform/wtf/WTF.h"
+#include "public/platform/WebURLRequest.h"
 
 namespace blink {
 
+namespace {
+
+WebURLRequest::FetchCredentialsMode ParseCredentialsOption(
+    const String& credentials_option) {
+  if (credentials_option == "omit")
+    return WebURLRequest::kFetchCredentialsModeOmit;
+  if (credentials_option == "same-origin")
+    return WebURLRequest::kFetchCredentialsModeSameOrigin;
+  if (credentials_option == "include")
+    return WebURLRequest::kFetchCredentialsModeInclude;
+  NOTREACHED();
+  return WebURLRequest::kFetchCredentialsModeOmit;
+}
+
+}  // namespace
+
 Worklet::Worklet(LocalFrame* frame)
     : ContextLifecycleObserver(frame->GetDocument()) {
   DCHECK(IsMainThread());
@@ -62,6 +81,74 @@ ScriptPromise Worklet::addModule(ScriptState* script_state,
   return promise;
 }
 
+void Worklet::ContextDestroyed(ExecutionContext* execution_context) {
+  DCHECK(IsMainThread());
+  for (const auto& proxy : proxies_)
+    proxy->TerminateWorkletGlobalScope();
+}
+
+WorkletGlobalScopeProxy* Worklet::FindAvailableGlobalScope() const {
+  DCHECK(IsMainThread());
+  // TODO(nhiroki): Support the case where there are multiple global scopes.
+  DCHECK_EQ(1u, GetNumberOfGlobalScopes());
+  return proxies_.begin()->get();
+}
+
+// Implementation of the second half of the "addModule(moduleURL, options)"
+// algorithm:
+// https://drafts.css-houdini.org/worklets/#dom-worklet-addmodule
+void Worklet::FetchAndInvokeScript(const KURL& module_url_record,
+                                   const WorkletOptions& options,
+                                   ScriptPromiseResolver* resolver) {
+  DCHECK(IsMainThread());
+  if (!GetExecutionContext())
+    return;
+
+  // 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());
+
+  // Step 7: "Let outsideSettings be the relevant settings object of this."
+  // TODO(nhiroki): outsideSettings will be used for posting a task to the
+  // document's responsible event loop. We could use a task runner for the
+  // purpose.
+
+  // Step 8: "Let moduleResponsesMap be worklet's module responses map."
+  // TODO(nhiroki): Implement moduleResponsesMap (https://crbug.com/627945).
+
+  // 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."
+  while (NeedsToCreateGlobalScope())
+    proxies_.insert(CreateGlobalScope());
+  DCHECK_LT(1u, GetNumberOfGlobalScopes());
+
+  // Step 11: "Let pendingTaskStruct be a new pending tasks struct with counter
+  // initialized to the length of worklet's WorkletGlobalScopes."
+  WorkletPendingTasks* pending_tasks =
+      new WorkletPendingTasks(GetNumberOfGlobalScopes(), 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.
+  for (const auto& proxy : proxies_) {
+    proxy->FetchAndInvokeScript(module_url_record, credentials_mode,
+                                pending_tasks);
+  }
+}
+
 DEFINE_TRACE(Worklet) {
   ContextLifecycleObserver::Trace(visitor);
 }