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/JSBundleLoader.java

@@ -0,0 +1,69 @@
+/**
+ * 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 android.content.res.AssetManager;
+
+/**
+ * A class that stores JS bundle information and allows {@link CatalystInstance} to load a correct
+ * bundle through {@link ReactBridge}.
+ */
+public abstract class JSBundleLoader {
+
+  /**
+   * This loader is recommended one for release version of your app. In that case local JS executor
+   * should be used. JS bundle will be read from assets directory in native code to save on passing
+   * large strings from java to native memory.
+   */
+  public static JSBundleLoader createAssetLoader(
+      final AssetManager assetManager,
+      final String assetFileName) {
+    return new JSBundleLoader() {
+      @Override
+      public void loadScript(ReactBridge bridge) {
+        bridge.loadScriptFromAssets(assetManager, assetFileName);
+      }
+    };
+  }
+
+  /**
+   * This loader is used when bundle gets reloaded from dev server. In that case loader expect JS
+   * bundle to be prefetched and stored in local file. We do that to avoid passing large strings
+   * between java and native code and avoid allocating memory in java to fit whole JS bundle in it.
+   * Providing correct {@param sourceURL} of downloaded bundle is required for JS stacktraces to
+   * work correctly and allows for source maps to correctly symbolize those.
+   */
+  public static JSBundleLoader createCachedBundleFromNetworkLoader(
+      final String sourceURL,
+      final String cachedFileLocation) {
+    return new JSBundleLoader() {
+      @Override
+      public void loadScript(ReactBridge bridge) {
+        bridge.loadScriptFromNetworkCached(sourceURL, cachedFileLocation);
+      }
+    };
+  }
+
+  /**
+   * This loader is used when proxy debugging is enabled. In that case there is no point in fetching
+   * the bundle from device as remote executor will have to do it anyway.
+   */
+  public static JSBundleLoader createRemoteDebuggerBundleLoader(
+      final String sourceURL) {
+    return new JSBundleLoader() {
+      @Override
+      public void loadScript(ReactBridge bridge) {
+        bridge.loadScriptFromNetworkCached(sourceURL, null);
+      }
+    };
+  }
+
+  public abstract void loadScript(ReactBridge bridge);
+}