Remove default AppContext and cleanup globals (#6999)
diff --git a/packages/flutter_tools/lib/src/device.dart b/packages/flutter_tools/lib/src/device.dart
index 1f9e7a2..67354df 100644
--- a/packages/flutter_tools/lib/src/device.dart
+++ b/packages/flutter_tools/lib/src/device.dart
@@ -9,6 +9,7 @@
import 'android/android_device.dart';
import 'application_package.dart';
import 'base/common.dart';
+import 'base/context.dart';
import 'base/os.dart';
import 'base/utils.dart';
import 'build_info.dart';
@@ -16,6 +17,8 @@
import 'ios/devices.dart';
import 'ios/simulators.dart';
+DeviceManager get deviceManager => context[DeviceManager];
+
/// A class to get all available devices.
class DeviceManager {
/// Constructing DeviceManagers is cheap; they only do expensive work if some
