Fix virtual/override/final usage in Source/bindings/.

Source/bindings/core/v8/ExceptionStatePlaceholder.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 29 matching lines @@
 namespace blink {
 
 class ExceptionState;
 
 typedef int ExceptionCode;
 
 class IgnorableExceptionState final : public ExceptionState {
 public:
     IgnorableExceptionState(): ExceptionState(ExceptionState::UnknownContext, 0, 0, v8::Local<v8::Object>(), 0) { }
     ExceptionState& returnThis() { return *this; }
-    virtual void throwDOMException(const ExceptionCode&, const String& message = String()) override { }
-    virtual void throwTypeError(const String& message = String()) override { }
-    virtual void throwSecurityError(const String& sanitizedMessage, const String& unsanitizedMessage = String()) override { }
+    void throwDOMException(const ExceptionCode&, const String& message = String()) override { }
+    void throwTypeError(const String& message = String()) override { }
+    void throwSecurityError(const String& sanitizedMessage, const String& unsanitizedMessage = String()) override { }
 };
 
 #define IGNORE_EXCEPTION (::blink::IgnorableExceptionState().returnThis())
 
 #if ENABLE(ASSERT)
 
 class CORE_EXPORT NoExceptionStateAssertionChecker final : public ExceptionState {
 public:
     NoExceptionStateAssertionChecker(const char* file, int line);
     ExceptionState& returnThis() { return *this; }
-    virtual void throwDOMException(const ExceptionCode&, const String& message = String()) override;
-    virtual void throwTypeError(const String& message = String()) override;
-    virtual void throwSecurityError(const String& sanitizedMessage, const String& unsanitizedMessage = String()) override;
+    void throwDOMException(const ExceptionCode&, const String& message = String()) override;
+    void throwTypeError(const String& message = String()) override;
+    void throwSecurityError(const String& sanitizedMessage, const String& unsanitizedMessage = String()) override;
 
 private:
     const char* m_file;
     int m_line;
 };
 
 #define ASSERT_NO_EXCEPTION (::blink::NoExceptionStateAssertionChecker(__FILE__, __LINE__).returnThis())
 
 #else
 
 #define ASSERT_NO_EXCEPTION (::blink::IgnorableExceptionState().returnThis())
 
 #endif
 
 } // namespace blink
 
 #endif // ExceptionStatePlaceholder_h