Add ability to customize error messages and stacks within the iOS redbox

Reviewed By: javache

Differential Revision: D3517605

fbshipit-source-id: a2efba80bbe1f6c74bf4e01f7807389962cb2463

React/Base/RCTErrorCustomizer.h

@@ -0,0 +1,25 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#import <Foundation/Foundation.h>
+
+@class RCTErrorInfo;
+
+/**
+ * Provides an interface to customize React Native error messages and stack
+ * traces from exceptions.
+ */
+@protocol RCTErrorCustomizer <NSObject>
+
+/**
+ * Customizes the given error, returning the passed info argument if no
+ * customization is required.
+ */
+- (nonnull RCTErrorInfo *)customizeErrorInfo:(nonnull RCTErrorInfo *)info;
+@end