Pdfium does not create isolate when it runs in chromium

fpdfsdk/src/fpdfxfa/fpdfxfa_app.cpp

 // 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
 
 #include "fpdfsdk/include/fsdk_define.h"
 #include "fpdfsdk/include/fsdk_mgr.h"
 #include "fpdfsdk/include/fpdfxfa/fpdfxfa_doc.h"
 #include "fpdfsdk/include/fpdfxfa/fpdfxfa_util.h"
@@ skipping 13 matching lines @@
 void CPDFXFA_App::ReleaseInstance() {
   delete g_pApp;
   g_pApp = NULL;
 }
 
 CPDFXFA_App::CPDFXFA_App()
     : m_bJavaScriptInitialized(FALSE),
       m_pXFAApp(NULL),
       m_pFontMgr(NULL),
       m_hJSERuntime(NULL),
-      m_csAppType(JS_STR_VIEWERTYPE_STANDARD) {
+      m_csAppType(JS_STR_VIEWERTYPE_STANDARD),
+      m_bOwnedRuntime(false) {
   m_pEnvList.RemoveAll();
 }
 
 CPDFXFA_App::~CPDFXFA_App() {
   delete m_pFontMgr;
   m_pFontMgr = NULL;
 
   delete m_pXFAApp;
   m_pXFAApp = NULL;
 
 #ifdef PDF_ENABLE_XFA
-  FXJSE_Runtime_Release(m_hJSERuntime);
+  FXJSE_Runtime_Release(m_hJSERuntime, m_bOwnedRuntime);
   m_hJSERuntime = NULL;
 
   FXJSE_Finalize();
   BC_Library_Destory();
 #endif
 }
 
-FX_BOOL CPDFXFA_App::Initialize() {
+FX_BOOL CPDFXFA_App::Initialize(FXJSE_HRUNTIME hRuntime) {
 #ifdef PDF_ENABLE_XFA
   BC_Library_Init();
   FXJSE_Initialize();
 
-  m_hJSERuntime = FXJSE_Runtime_Create();
+  m_bOwnedRuntime = !hRuntime;
+  m_hJSERuntime = hRuntime ? hRuntime : FXJSE_Runtime_Create();
   if (!m_hJSERuntime)
     return FALSE;
 
   m_pXFAApp = IXFA_App::Create(this);
   if (!m_pXFAApp)
     return FALSE;
 
   m_pFontMgr = IXFA_FontMgr::CreateDefault();
   if (!m_pFontMgr)
     return FALSE;
@@ skipping 458 matching lines @@
   return FALSE;
 }
 
 IFWL_AdapterTimerMgr* CPDFXFA_App::GetTimerMgr() {
   CXFA_FWLAdapterTimerMgr* pAdapter = NULL;
   CPDFDoc_Environment* pEnv = m_pEnvList.GetAt(0);
   if (pEnv)
     pAdapter = new CXFA_FWLAdapterTimerMgr(pEnv);
   return pAdapter;
 }