Add ReactInstanceHolder

Reviewed By: astreet

Differential Revision: D3328342

fbshipit-source-id: af4e825d0b7c2d3d4490094a939e97cc527dd242

ReactAndroid/src/main/java/com/facebook/react/ReactApplication.java

@@ -0,0 +1,18 @@
+/**
+ * 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.
+ */
+
+package com.facebook.react;
+
+public interface ReactApplication {
+
+  /**
+   * Get the default {@link ReactNativeHost} for this app.
+   */
+  ReactNativeHost getReactNativeHost();
+}