Remove out of date duplicate TryUnwrapObject implementation. (#235)

WinRT.Runtime/Marshalers.cs

@@ -923,7 +923,7 @@ public static IObjectReference CreateMarshaler(object o, bool unwrapObject = tru
  return null;
  }
 
- if (unwrapObject && TryUnwrapObject(o, out var objRef))
+ if (unwrapObject && ComWrappersSupport.TryUnwrapObject(o, out var objRef))
  {
  return objRef.As<IInspectable.Vftbl>();
  }
@@ -975,36 +975,6 @@ public static unsafe void CopyManaged(object o, IntPtr dest, bool unwrapObject =
  *(IntPtr*)dest.ToPointer() = objRef?.GetRef() ?? IntPtr.Zero;
  }
 
- private static bool TryUnwrapObject(object o, out IObjectReference objRef)
- {
- // The unwrapping here needs to be in exact type match in case the user
- // has implemented a WinRT interface or inherited from a WinRT class
- // in a .NET (non-projected) type.
-
- // TODO: Define and output attributes defining that a type is a projected interface
- // or class type to avoid accidental collisions.
- // Also, it might be a good idea to add a property to get the IObjectReference
- // that is marked [EditorBrowsable(EditorBrowsableState.Never)] to hide it from most IDEs
- // to help avoid using private implementation details.
- Type type = o.GetType();
- // Projected interface types have fields name _obj that hold their object reference.
- objRef = (IObjectReference)type.GetField("_obj", BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.DeclaredOnly)?.GetValue(o);
- if (objRef != null)
- {
- return true;
- }
-
- // If we get here, we're either a class or a non-WinRT type. If we're a class, we'll have a _default field holding a reference to our default interface.
- object defaultInterface = type.GetField("_default", BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.DeclaredOnly)?.GetValue(o);
- if (defaultInterface != null)
- {
- return TryUnwrapObject(defaultInterface, out objRef);
- }
-
- objRef = null;
- return false;
- }
-
  public static unsafe MarshalInterfaceHelper<object>.MarshalerArray CreateMarshalerArray(object[] array) => MarshalInterfaceHelper<object>.CreateMarshalerArray(array, (o) => CreateMarshaler(o));
 
  public static (int length, IntPtr data) GetAbiArray(object box) => MarshalInterfaceHelper<object>.GetAbiArray(box);