src/api-impl/android/view/Choreographer.java: implement enough for games using swappy to work (tested with sample Unity app)

src/api-impl/android/view/Choreographer.java

@@ -1,5 +1,25 @@
 package android.view;
 
 public final class Choreographer {
-	public static interface FrameCallback {}
+	public static interface FrameCallback {
+	    public void doFrame(long frametime_in_nanoseconds);
+	}
+
+	public static Choreographer getInstance() {
+		return new Choreographer();
+	}
+
+	public void postFrameCallback(Choreographer.FrameCallback callback) {
+		postFrameCallbackDelayed(callback, 0);
+	}
+
+	public void postFrameCallbackDelayed(final Choreographer.FrameCallback callback, long delayMillis) {
+		// TODO - do the delay part
+		// NOTE: if we do this synchronously, it gets stuck
+		Thread async = new Thread(new Runnable() {
+		public void run() {
+			callback.doFrame(System.nanoTime());
+		}});
+		async.start();
+	}
 }