Cross platform ActivityIndicator

Summary:
The API for `ActivityIndiatorIOS` and `ProgressBarAndroid` is very similar and can be merged in a cross platform component that displays a circular indeterminate loading indicator.

This deprecates `ActivityIndiatorIOS` and non-horizontal `ProgressBarAndroid` in favor of this new component.

**Test plan (required)**

Tested with the ActivityIndicator example in UIExplorer on android and ios. Also made sure that `ActivityIndicatorIOS` still works and displays a deprecation warning. Also tested that `ProgressBarAndroid` with `indeterminate == true` and `styleAttr != 'Horizontal'` displays a deprecation warning.
Closes https://github.com/facebook/react-native/pull/6897

Differential Revision: D3351607

Pulled By: dmmiller

fbshipit-source-id: b107ce99d966359003e8b3118cd97b90fa1d3d7d

Libraries/Components/ActivityIndicator/ActivityIndicatorIOS.ios.js

@@ -0,0 +1,63 @@
+/**
+ * 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.
+ *
+ * @providesModule ActivityIndicatorIOS
+ */
+'use strict';
+
+var ActivityIndicator = require('ActivityIndicator');
+var NativeMethodsMixin = require('NativeMethodsMixin');
+var PropTypes = require('ReactPropTypes');
+var React = require('React');
+var View = require('View');
+
+/**
+ * Deprecated, use ActivityIndicator instead.
+ */
+var ActivityIndicatorIOS = React.createClass({
+  mixins: [NativeMethodsMixin],
+
+  propTypes: {
+    ...View.propTypes,
+    /**
+     * Whether to show the indicator (true, the default) or hide it (false).
+     */
+    animating: PropTypes.bool,
+    /**
+     * The foreground color of the spinner (default is gray).
+     */
+    color: PropTypes.string,
+    /**
+     * Whether the indicator should hide when not animating (true by default).
+     */
+    hidesWhenStopped: PropTypes.bool,
+    /**
+     * Size of the indicator. Small has a height of 20, large has a height of 36.
+     */
+    size: PropTypes.oneOf([
+      'small',
+      'large',
+    ]),
+    /**
+     * Invoked on mount and layout changes with
+     *
+     *   {nativeEvent: { layout: {x, y, width, height}}}.
+     */
+    onLayout: PropTypes.func,
+  },
+
+  componentDidMount: function() {
+    console.warn('ActivityIndicatorIOS is deprecated. Use ActivityIndicator instead.');
+  },
+
+  render: function() {
+    return <ActivityIndicator {...this.props} />;
+  }
+});
+
+module.exports = ActivityIndicatorIOS;