-Add a mojo service to get video frames from the camera through an android service

examples/dart/camera_roll/camera_roll.dart

-#!mojo sky_viewer.mojo
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// To run: mojo/devtools/common/mojo_run --sky \
-//             examples/dart/camera_roll/camera_roll.dart --android
-// This example makes use of mojo:camera_roll which is available only when
-// running on Android.
-
-import 'dart:async';
-import 'dart:sky';
-
-import 'package:mojom/mojo/camera_roll.mojom.dart';
-import 'package:sky/mojo/embedder.dart';
-
-final CameraRollServiceProxy cameraRoll = new CameraRollServiceProxy.unbound();
-int photoIndex = 0;
-
-Picture draw(Image image) {
-  PictureRecorder canvas = new PictureRecorder(view.width, view.height);
-  Paint paint = new Paint()..color = const Color.fromARGB(255, 0, 255, 0);
-  canvas.scale(view.width / image.width, view.height / image.height);
-  canvas.drawImage(image, 0.0, 0.0, paint);
-  return canvas.endRecording();
-}
-
-void drawNextPhoto() {
-  var future = cameraRoll.ptr.getPhoto(photoIndex);
-  future.then((response) {
-    if (response.photo == null) {
-      cameraRoll.ptr.update();
-      photoIndex = 0;
-      drawNextPhoto();
-      return;
-    }
-
-    new ImageDecoder(response.photo.content.handle.h, (image) {
-      if (image != null) {
-        view.picture = draw(image);
-        view.scheduleFrame();
-      }
-    });
-  });
-}
-
-bool handleEvent(Event event) {
-  if (event.type == "pointerdown") {
-    return true;
-  }
-
-  if (event.type == "pointerup") {
-    photoIndex++;
-    drawNextPhoto();
-    return true;
-  }
-
-  return false;
-}
-
-void main() {
-  embedder.connectToService("mojo:camera_roll", cameraRoll);
-  view.setEventCallback(handleEvent);
-  drawNextPhoto();
-}