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/GuardedAsyncTask.java

@@ -0,0 +1,43 @@
+/**
+ * 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.os.AsyncTask;
+
+/**
+ * Abstract base for a AsyncTask that should have any RuntimeExceptions it throws
+ * handled by the {@link com.facebook.react.bridge.NativeModuleCallExceptionHandler} registered if
+ * the app is in dev mode.
+ *
+ * This class doesn't allow doInBackground to return a results. This is mostly because when this
+ * class was written that functionality wasn't used and it would require some extra code to make
+ * work correctly with caught exceptions. Don't let that stop you from adding it if you need it :)
+ */
+public abstract class GuardedAsyncTask<Params, Progress>
+    extends AsyncTask<Params, Progress, Void> {
+
+  private final ReactContext mReactContext;
+
+  protected GuardedAsyncTask(ReactContext reactContext) {
+    mReactContext = reactContext;
+  }
+
+  @Override
+  protected final Void doInBackground(Params... params) {
+    try {
+      doInBackgroundGuarded(params);
+    } catch (RuntimeException e) {
+      mReactContext.handleException(e);
+    }
+    return null;
+  }
+
+  protected abstract void doInBackgroundGuarded(Params... params);
+}