Push v8::Isolate into CFXJS_Engine class

testing/js_embedder_test.h

 // Copyright 2015 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef TESTING_JS_EMBEDDER_TEST_H_
 #define TESTING_JS_EMBEDDER_TEST_H_
 
 #include <memory>
 #include <vector>
 
 #include "fxjs/include/fxjs_v8.h"
 #include "testing/embedder_test.h"
 
 class JSEmbedderTest : public EmbedderTest {
  public:
   JSEmbedderTest();
   ~JSEmbedderTest() override;
 
   void SetUp() override;
   void TearDown() override;
 
   v8::Isolate* isolate();
   v8::Local<v8::Context> GetV8Context();
+  CFXJS_Engine* engine() { return m_Engine.get(); }
 
  private:
   std::unique_ptr<FXJS_ArrayBufferAllocator> m_pArrayBufferAllocator;
   v8::Isolate* m_pIsolate;
-  v8::Global<v8::Context> m_pPersistentContext;
-  std::vector<v8::Global<v8::Object>*> m_StaticObjects;
+  std::unique_ptr<CFXJS_Engine> m_Engine;
 };
 
 #endif  // TESTING_JS_EMBEDDER_TEST_H_