Added IsConstructorCall to gin::Arguments.

gin/arguments.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef GIN_ARGUMENTS_H_
 #define GIN_ARGUMENTS_H_
 
 #include "base/basictypes.h"
 #include "gin/converter.h"
 #include "gin/gin_export.h"
@@ skipping 61 matching lines @@
     info_->GetReturnValue().Set(ConvertToV8(isolate_, val));
   }
 
   v8::Handle<v8::Value> PeekNext() const;
 
   void ThrowError() const;
   void ThrowTypeError(const std::string& message) const;
 
   v8::Isolate* isolate() const { return isolate_; }
 
+  // Allows the function handler to distinguish between normal invocation
+  // and object construction.
+  bool IsConstructCall() const;
+
  private:
   v8::Isolate* isolate_;
   const v8::FunctionCallbackInfo<v8::Value>* info_;
   int next_;
   bool insufficient_arguments_;
 };
 
 }  // namespace gin
 
 #endif  // GIN_ARGUMENTS_H_