Remove unused CJS_Object::ExitInstance() method

All the work happens in the virtual dtors like it should.

Review-Url: https://codereview.chromium.org/2628843003

fpdfsdk/javascript/JS_Define.h

diff --git a/fpdfsdk/javascript/JS_Define.h b/fpdfsdk/javascript/JS_Define.h
index 17dd8e9..feab4d1 100644
--- a/fpdfsdk/javascript/JS_Define.h
+++ b/fpdfsdk/javascript/JS_Define.h
@@ -261,7 +261,6 @@
                                    v8::Local<v8::Object> obj) {              \
     js_class_name* pObj =                                                    \
         static_cast<js_class_name*>(pEngine->GetObjectPrivate(obj));         \
-    pObj->ExitInstance();                                                    \
     delete pObj;                                                             \
   }                                                                          \
   void js_class_name::DefineProps(CFXJS_Engine* pEngine) {                   \

fpdfsdk/javascript/JS_Object.cpp

diff --git a/fpdfsdk/javascript/JS_Object.cpp b/fpdfsdk/javascript/JS_Object.cpp
index 88dd288..9ef6cdd 100644
--- a/fpdfsdk/javascript/JS_Object.cpp
+++ b/fpdfsdk/javascript/JS_Object.cpp
@@ -16,7 +16,6 @@
 
 void FreeObject(const v8::WeakCallbackInfo<CJS_Object>& data) {
   CJS_Object* pJSObj = data.GetParameter();
-  pJSObj->ExitInstance();
   delete pJSObj;
   CFXJS_Engine::FreeObjectPrivate(data.GetInternalField(0));
 }
@@ -44,5 +43,3 @@
 }
 
 void CJS_Object::InitInstance(IJS_Runtime* pIRuntime) {}
-
-void CJS_Object::ExitInstance() {}

fpdfsdk/javascript/JS_Object.h

diff --git a/fpdfsdk/javascript/JS_Object.h b/fpdfsdk/javascript/JS_Object.h
index c6491e2..658a5e2 100644
--- a/fpdfsdk/javascript/JS_Object.h
+++ b/fpdfsdk/javascript/JS_Object.h
@@ -38,7 +38,6 @@
   void Dispose();
 
   virtual void InitInstance(IJS_Runtime* pIRuntime);
-  virtual void ExitInstance();
 
   v8::Local<v8::Object> ToV8Object() { return m_pV8Object.Get(m_pIsolate); }