Release React Native for Android

This is an early release and there are several things that are known
not to work if you're porting your iOS app to Android.

See the Known Issues guide on the website.

We will work with the community to reach platform parity with iOS.

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

@@ -0,0 +1,75 @@
+/**
+ * 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;
+
+import com.facebook.jni.Countable;
+import com.facebook.proguard.annotations.DoNotStrip;
+import com.facebook.soloader.SoLoader;
+
+/**
+ * Implementation of a read-only map in native memory. This will generally be constructed and filled
+ * in native code so you shouldn't construct one yourself.
+ */
+@DoNotStrip
+public class ReadableNativeMap extends NativeMap implements ReadableMap {
+
+  static {
+    SoLoader.loadLibrary(ReactBridge.REACT_NATIVE_LIB);
+  }
+
+  @Override
+  public native boolean hasKey(String name);
+  @Override
+  public native boolean isNull(String name);
+  @Override
+  public native boolean getBoolean(String name);
+  @Override
+  public native double getDouble(String name);
+  @Override
+  public native String getString(String name);
+  @Override
+  public native ReadableNativeArray getArray(String name);
+  @Override
+  public native ReadableNativeMap getMap(String name);
+  @Override
+  public native ReadableType getType(String name);
+
+  @Override
+  public ReadableMapKeySeyIterator keySetIterator() {
+    return new ReadableNativeMapKeySeyIterator(this);
+  }
+
+  @Override
+  public int getInt(String name) {
+    return (int) getDouble(name);
+  }
+
+  /**
+   * Implementation of a {@link ReadableNativeMap} iterator in native memory.
+   */
+  @DoNotStrip
+  private static class ReadableNativeMapKeySeyIterator extends Countable
+      implements ReadableMapKeySeyIterator {
+
+    private final ReadableNativeMap mReadableNativeMap;
+
+    public ReadableNativeMapKeySeyIterator(ReadableNativeMap readableNativeMap) {
+      mReadableNativeMap = readableNativeMap;
+      initialize(mReadableNativeMap);
+    }
+
+    @Override
+    public native boolean hasNextKey();
+    @Override
+    public native String nextKey();
+
+    private native void initialize(ReadableNativeMap readableNativeMap);
+  }
+}