[ES6 modules] Fix context leak. ModuleScript should use TraceWrapperV8Reference to hold onto v8::Mo…

third_party/WebKit/Source/core/loader/modulescript/ModuleTreeLinkerTest.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/loader/modulescript/ModuleTreeLinker.h"
 
 #include "bindings/core/v8/ScriptModule.h"
 #include "bindings/core/v8/V8BindingForCore.h"
 #include "bindings/core/v8/V8BindingForTesting.h"
 #include "core/dom/Modulator.h"
@@ skipping 128 matching lines @@
     EXPECT_TRUE(result_map.is_new_entry);
 
     pending_client->NotifyModuleTreeLoadFinished(module_script);
   }
 
   void SetInstantiateShouldFail(bool b) { instantiate_should_fail_ = b; }
 
  private:
   // Implements Modulator:
 
+  ScriptState* GetScriptState() override { return script_state_.Get(); }
+
   void FetchSingle(const ModuleScriptFetchRequest& request,
                    ModuleGraphLevel,
                    SingleModuleClient* client) override {
     pending_request_url_ = request.Url();
     EXPECT_FALSE(pending_client_);
     pending_client_ = client;
   }
 
   void FetchTreeInternal(const ModuleScriptFetchRequest& request,
                          const AncestorList& list,
@@ skipping 366 matching lines @@
   auto ancestor_list = GetModulator()->GetAncestorListForTreeFetch(url);
   EXPECT_EQ(0u, ancestor_list.size());
 
   EXPECT_TRUE(client->WasNotifyFinished());
   ASSERT_TRUE(client->GetModuleScript());
   EXPECT_EQ(client->GetModuleScript()->InstantiationState(),
             ModuleInstantiationState::kInstantiated);
 }
 
 }  // namespace blink