Fix XFA compilation noise, part 1.

Mainly:
  volatile/override/method shadowing.
  unused variables.
  intialization list init order.

R=thestig@chromium.org

Review URL: https://codereview.chromium.org/1422113003 .
diff --git a/fpdfsdk/src/javascript/JS_Runtime.h b/fpdfsdk/src/javascript/JS_Runtime.h
index 4772823..01a8827 100644
--- a/fpdfsdk/src/javascript/JS_Runtime.h
+++ b/fpdfsdk/src/javascript/JS_Runtime.h
@@ -57,10 +57,11 @@
   v8::Isolate* GetIsolate() const { return m_isolate; }
   v8::Local<v8::Context> NewJSContext();
 
-  virtual FX_BOOL GetHValueByName(const CFX_ByteStringC& utf8Name,
-                                  FXJSE_HVALUE hValue);
-  virtual FX_BOOL SetHValueByName(const CFX_ByteStringC& utf8Name,
-                                  FXJSE_HVALUE hValue);
+  // IJS_Runtime:
+  FX_BOOL GetHValueByName(const CFX_ByteStringC& utf8Name,
+                          FXJSE_HVALUE hValue) override;
+  FX_BOOL SetHValueByName(const CFX_ByteStringC& utf8Name,
+                          FXJSE_HVALUE hValue) override;
 
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);