Bug 1362119 - part 2 - Splitting ScriptLoader in multiple files, r=ehsan

This patch it's huge because I use hg cp in order to keep the history/blame
during the moving.

dom/script/ModuleScript.cpp

@@ -0,0 +1,96 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ModuleScript.h"
+#include "mozilla/HoldDropJSObjects.h"
+#include "ScriptLoader.h"
+
+namespace mozilla {
+namespace dom {
+
+// A single module script.  May be used to satisfy multiple load requests.
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ModuleScript)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(ModuleScript)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(ModuleScript)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mLoader)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mBaseURL)
+  tmp->UnlinkModuleRecord();
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(ModuleScript)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mLoader)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(ModuleScript)
+  NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mModuleRecord)
+  NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mException)
+NS_IMPL_CYCLE_COLLECTION_TRACE_END
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(ModuleScript)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(ModuleScript)
+
+ModuleScript::ModuleScript(ScriptLoader *aLoader, nsIURI* aBaseURL,
+                           JS::Handle<JSObject*> aModuleRecord)
+ : mLoader(aLoader),
+   mBaseURL(aBaseURL),
+   mModuleRecord(aModuleRecord),
+   mInstantiationState(Uninstantiated)
+{
+  MOZ_ASSERT(mLoader);
+  MOZ_ASSERT(mBaseURL);
+  MOZ_ASSERT(mModuleRecord);
+  MOZ_ASSERT(mException.isUndefined());
+
+  // Make module's host defined field point to this module script object.
+  // This is cleared in the UnlinkModuleRecord().
+  JS::SetModuleHostDefinedField(mModuleRecord, JS::PrivateValue(this));
+  HoldJSObjects(this);
+}
+
+void
+ModuleScript::UnlinkModuleRecord()
+{
+  // Remove module's back reference to this object request if present.
+  if (mModuleRecord) {
+    MOZ_ASSERT(JS::GetModuleHostDefinedField(mModuleRecord).toPrivate() ==
+               this);
+    JS::SetModuleHostDefinedField(mModuleRecord, JS::UndefinedValue());
+  }
+  mModuleRecord = nullptr;
+  mException.setUndefined();
+}
+
+ModuleScript::~ModuleScript()
+{
+  if (mModuleRecord) {
+    // The object may be destroyed without being unlinked first.
+    UnlinkModuleRecord();
+  }
+  DropJSObjects(this);
+}
+
+void
+ModuleScript::SetInstantiationResult(JS::Handle<JS::Value> aMaybeException)
+{
+  MOZ_ASSERT(mInstantiationState == Uninstantiated);
+  MOZ_ASSERT(mModuleRecord);
+  MOZ_ASSERT(mException.isUndefined());
+
+  if (aMaybeException.isUndefined()) {
+    mInstantiationState = Instantiated;
+  } else {
+    mModuleRecord = nullptr;
+    mException = aMaybeException;
+    mInstantiationState = Errored;
+  }
+}
+
+} // dom namespace
+} // mozilla namespace