Make code compile with clang_use_chrome_plugin (part IV)

This change mainly contains files in fpdfsdk/ directory.
This is part of the efforts to make PDFium code compilable
by Clang chromium style plugins.

The changes are mainly the following:
-- move inline constructor/destructor of complex class/struct out-of-line;
-- add constructor/destructor of complex class/struct if not
 explicitly defined;
-- add explicit out-of-line copy constructor when needed;
-- move inline virtual functions out-of-line;
-- Properly mark virtual functions with 'override';
-- some minor cleanups plus removing an unused file and splitting
cxfa_eventparam out from fxfa.h

BUG=pdfium:469

Review-Url: https://codereview.chromium.org/2062313002
diff --git a/fpdfsdk/javascript/JS_Value.h b/fpdfsdk/javascript/JS_Value.h
index 8adec4b..958c5e0 100644
--- a/fpdfsdk/javascript/JS_Value.h
+++ b/fpdfsdk/javascript/JS_Value.h
@@ -46,6 +46,7 @@
   CJS_Value(CJS_Runtime* pRuntime, CJS_Array& array);
 
   ~CJS_Value();
+  CJS_Value(const CJS_Value& other);
 
   void SetNull();
   void Attach(v8::Local<v8::Value> pValue, Type t);
@@ -137,6 +138,7 @@
  public:
   CJS_Array(CJS_Runtime* pRuntime);
   virtual ~CJS_Array();
+  CJS_Array(const CJS_Array& other);
 
   void Attach(v8::Local<v8::Array> pArray);
   void GetElement(unsigned index, CJS_Value& value);