[ES6 modules] Introduce ScriptModuleHash

third_party/WebKit/Source/bindings/core/v8/ScriptModule.cpp

Index: third_party/WebKit/Source/bindings/core/v8/ScriptModule.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/ScriptModule.cpp b/third_party/WebKit/Source/bindings/core/v8/ScriptModule.cpp
index 3642e50d29e06bf845e1c80fa82a44cdbdc378f8..0de9985ed31c8e083ed8d72eee72763ab8808b8d 100644
--- a/third_party/WebKit/Source/bindings/core/v8/ScriptModule.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/ScriptModule.cpp
@@ -9,7 +9,10 @@
 namespace blink {
 
 ScriptModule::ScriptModule(v8::Isolate* isolate, v8::Local<v8::Module> module)
-    : m_module(SharedPersistent<v8::Module>::create(module, isolate)) {}
+    : m_module(SharedPersistent<v8::Module>::create(module, isolate)),
+      m_identityHash(static_cast<unsigned>(module->GetIdentityHash())) {
+  DCHECK(!m_module.isEmpty());
+}
 
 ScriptModule::~ScriptModule() {}