Remove unused CJS_Value::Attach() variant

Review-Url: https://codereview.chromium.org/2174513002
diff --git a/fpdfsdk/javascript/JS_Value.cpp b/fpdfsdk/javascript/JS_Value.cpp
index 5c1ba2a..c13d1d4 100644
--- a/fpdfsdk/javascript/JS_Value.cpp
+++ b/fpdfsdk/javascript/JS_Value.cpp
@@ -75,11 +75,6 @@
   m_pValue = pValue;
 }
 
-void CJS_Value::Attach(CJS_Value* pValue) {
-  if (pValue)
-    Attach(pValue->ToV8Value());
-}
-
 void CJS_Value::Detach() {
   m_pValue = v8::Local<v8::Value>();
 }
diff --git a/fpdfsdk/javascript/JS_Value.h b/fpdfsdk/javascript/JS_Value.h
index 8e79125..2abc425 100644
--- a/fpdfsdk/javascript/JS_Value.h
+++ b/fpdfsdk/javascript/JS_Value.h
@@ -31,7 +31,7 @@
     VT_undefined
   };
 
-  CJS_Value(CJS_Runtime* pRuntime);
+  explicit CJS_Value(CJS_Runtime* pRuntime);
   CJS_Value(CJS_Runtime* pRuntime, v8::Local<v8::Value> pValue);
   CJS_Value(CJS_Runtime* pRuntime, const int& iValue);
   CJS_Value(CJS_Runtime* pRuntime, const double& dValue);
@@ -41,13 +41,12 @@
   CJS_Value(CJS_Runtime* pRuntime, const FX_CHAR* pStr);
   CJS_Value(CJS_Runtime* pRuntime, const FX_WCHAR* pWstr);
   CJS_Value(CJS_Runtime* pRuntime, CJS_Array& array);
+  CJS_Value(const CJS_Value& other);
 
   ~CJS_Value();
-  CJS_Value(const CJS_Value& other);
 
   void SetNull();
   void Attach(v8::Local<v8::Value> pValue);
-  void Attach(CJS_Value* pValue);
   void Detach();
 
   static Type GetValueType(v8::Local<v8::Value> value);