Add dynamic type for javascript arguments passed over bridge with unkown type

Reviewed By: astreet

Differential Revision: D4380882

fbshipit-source-id: f1b9fb9cf727d003dcc2264626e75fc300a47dee

ReactAndroid/src/main/java/com/facebook/react/bridge/DynamicFromMap.java

@@ -0,0 +1,59 @@
+/**
+ * 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.bridge;
+
+/**
+ * Implementation of Dynamic wrapping a ReadableMap.
+ */
+public class DynamicFromMap implements Dynamic {
+
+  private final ReadableMap mMap;
+  private final String mName;
+
+  public DynamicFromMap(ReadableMap map, String name) {
+    mMap = map;
+    mName = name;
+  }
+
+  @Override
+  public boolean asBoolean() {
+    return mMap.getBoolean(mName);
+  }
+
+  @Override
+  public double asDouble() {
+    return mMap.getDouble(mName);
+  }
+
+  @Override
+  public int asInt() {
+    return mMap.getInt(mName);
+  }
+
+  @Override
+  public String asString() {
+    return mMap.getString(mName);
+  }
+
+  @Override
+  public ReadableArray asArray() {
+    return mMap.getArray(mName);
+  }
+
+  @Override
+  public ReadableMap asMap() {
+    return mMap.getMap(mName);
+  }
+
+  @Override
+  public ReadableType getType() {
+    return mMap.getType(mName);
+  }
+}