IDL: Support argument default values

Source/bindings/v8/V8Binding.h

 /*
 * Copyright (C) 2009 Google Inc. All rights reserved.
 * Copyright (C) 2012 Ericsson AB. 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.
@@ skipping 64 matching lines @@
 // Helpers for throwing JavaScript TypeErrors for arity mismatches.
 void throwArityTypeErrorForMethod(const char* method, const char* type, const char* valid, unsigned provided, v8::Isolate*);
 void throwArityTypeErrorForConstructor(const char* type, const char* valid, unsigned provided, v8::Isolate*);
 void throwArityTypeError(ExceptionState&, const char* valid, unsigned provided);
 void throwMinimumArityTypeErrorForMethod(const char* method, const char* type, unsigned expected, unsigned providedLeastNumMandatoryParams, v8::Isolate*);
 void throwMinimumArityTypeErrorForConstructor(const char* type, unsigned expected, unsigned providedLeastNumMandatoryParams, v8::Isolate*);
 void throwMinimumArityTypeError(ExceptionState&, unsigned expected, unsigned providedLeastNumMandatoryParams);
 
 v8::ArrayBuffer::Allocator* v8ArrayBufferAllocator();
 
-inline v8::Handle<v8::Value> argumentOrNull(const v8::FunctionCallbackInfo<v8::Value>& info, int index)
-{
-    return index >= info.Length() ? v8::Local<v8::Value>() : info[index];
-}
-
 template<typename CallbackInfo, typename V>
 inline void v8SetReturnValue(const CallbackInfo& info, V v)
 {
     info.GetReturnValue().Set(v);
 }
 
 template<typename CallbackInfo>
 inline void v8SetReturnValueBool(const CallbackInfo& info, bool v)
 {
     info.GetReturnValue().Set(v);
@@ skipping 863 matching lines @@
         m_block.Reset();
     }
 
 private:
     v8::TryCatch& m_block;
 };
 
 } // namespace WebCore
 
 #endif // V8Binding_h