Introduce ModuleScript::CreateInternal()

This is preparation for https://codereview.chromium.org/2850673002
to create a place to insert RegisterModuleScript() both for
Create() and CreateForTest().

This doesn't change the behavior.

BUG=594639, 715369

Review-Url: https://codereview.chromium.org/2844413003
Cr-Commit-Position: refs/heads/master@{#467891}

third_party/WebKit/Source/core/dom/ModuleScript.cpp

@@ -18,6 +18,7 @@ ModuleScript* ModuleScript::Create(
     ParserDisposition parser_state,
     WebURLRequest::FetchCredentialsMode credentials_mode,
     AccessControlStatus access_control_status) {
+  // https://html.spec.whatwg.org/#creating-a-module-script
   // Step 1. Let script be a new module script that this algorithm will
   // subsequently initialize.
   // Step 2. Set script's settings object to the environment settings object
@@ -30,6 +31,19 @@ ModuleScript* ModuleScript::Create(
   // Step 6: "...return null, and abort these steps."
   if (result.IsNull())
     return nullptr;
+
+  return CreateInternal(modulator, result, base_url, nonce, parser_state,
+                        credentials_mode);
+}
+
+ModuleScript* ModuleScript::CreateInternal(
+    Modulator* modulator,
+    ScriptModule result,
+    const KURL& base_url,
+    const String& nonce,
+    ParserDisposition parser_state,
+    WebURLRequest::FetchCredentialsMode credentials_mode) {
+  // https://html.spec.whatwg.org/#creating-a-module-script
   // Step 7. Set script's module record to result.
   // Step 8. Set script's base URL to the script base URL provided.
   // Step 9. Set script's cryptographic nonce to the cryptographic nonce
@@ -41,6 +55,17 @@ ModuleScript* ModuleScript::Create(
                           credentials_mode);
 }
 
+ModuleScript* ModuleScript::CreateForTest(
+    Modulator* modulator,
+    ScriptModule record,
+    const KURL& base_url,
+    const String& nonce,
+    ParserDisposition parser_state,
+    WebURLRequest::FetchCredentialsMode credentials_mode) {
+  return CreateInternal(modulator, record, base_url, nonce, parser_state,
+                        credentials_mode);
+}
+
 void ModuleScript::SetInstantiationErrorAndClearRecord(ScriptValue error) {
   // Implements Step 7.1 of:
   // https://html.spec.whatwg.org/multipage/webappapis.html#internal-module-script-graph-fetching-procedure

third_party/WebKit/Source/core/dom/ModuleScript.h

@@ -39,16 +39,15 @@ class CORE_EXPORT ModuleScript final : public Script, public TraceWrapperBase {
                               WebURLRequest::FetchCredentialsMode,
                               AccessControlStatus);
 
-  static ModuleScript* CreateForTest(
-      Modulator* settings_object,
-      ScriptModule record,
-      const KURL& base_url,
-      const String& nonce,
-      ParserDisposition parser_state,
-      WebURLRequest::FetchCredentialsMode credentials_mode) {
-    return new ModuleScript(settings_object, record, base_url, nonce,
-                            parser_state, credentials_mode);
-  }
+  // Mostly corresponds to Create() but accepts ScriptModule as the argument
+  // and allows null ScriptModule.
+  static ModuleScript* CreateForTest(Modulator*,
+                                     ScriptModule,
+                                     const KURL& base_url,
+                                     const String& nonce,
+                                     ParserDisposition,
+                                     WebURLRequest::FetchCredentialsMode);
+
   ~ModuleScript() override = default;
 
   const ScriptModule& Record() const { return record_; }
@@ -89,6 +88,13 @@ class CORE_EXPORT ModuleScript final : public Script, public TraceWrapperBase {
         parser_state_(parser_state),
         credentials_mode_(credentials_mode) {}
 
+  static ModuleScript* CreateInternal(Modulator*,
+                                      ScriptModule,
+                                      const KURL& base_url,
+                                      const String& nonce,
+                                      ParserDisposition,
+                                      WebURLRequest::FetchCredentialsMode);
+
   ScriptType GetScriptType() const override { return ScriptType::kModule; }
   bool IsEmpty() const override;
   bool CheckMIMETypeBeforeRunScript(Document* context_document,