Keep "static" objects per-context rather than per isolate.

fpdfsdk/src/javascript/JS_Runtime.h

 // Copyright 2014 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.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef FPDFSDK_SRC_JAVASCRIPT_JS_RUNTIME_H_
 #define FPDFSDK_SRC_JAVASCRIPT_JS_RUNTIME_H_
 
 #include <set>
 #include <utility>
+#include <vector>
 
 #include "../../include/javascript/IJavaScript.h"
 #include "../../include/jsapi/fxjs_v8.h"
 #include "JS_EventHandler.h"
 #include "core/include/fxcrt/fx_basic.h"
 
 class CJS_Context;
 
 class CJS_Runtime : public IJS_Runtime {
  public:
@@ skipping 42 matching lines @@
   void DefineJSObjects();
 
   CFX_ArrayTemplate<CJS_Context*> m_ContextArray;
   CPDFDoc_Environment* m_pApp;
   CPDFSDK_Document* m_pDocument;
   FX_BOOL m_bBlocking;
   std::set<FieldEvent> m_FieldEventSet;
   v8::Isolate* m_isolate;
   bool m_isolateManaged;
   v8::Global<v8::Context> m_context;
+  std::vector<v8::Global<v8::Object>*> m_StaticObjects;
   std::set<Observer*> m_observers;
 };
 
 #endif  // FPDFSDK_SRC_JAVASCRIPT_JS_RUNTIME_H_