Fix lint issues causing CI to fail (flutter#825)

lib/camera.dart

@@ -54,11 +54,11 @@ Future<List<CameraDescription>> availableCameras() async {
 }
 
 class CameraDescription {
+  CameraDescription({this.name, this.lensDirection});
+
   final String name;
   final CameraLensDirection lensDirection;
 
-  CameraDescription({this.name, this.lensDirection});
-
   @override
   bool operator ==(Object o) {
     return o is CameraDescription &&
@@ -79,21 +79,21 @@ class CameraDescription {
 
 /// This is thrown when the plugin reports an error.
 class CameraException implements Exception {
+  CameraException(this.code, this.description);
+
   String code;
   String description;
 
-  CameraException(this.code, this.description);
-
   @override
   String toString() => '$runtimeType($code, $description)';
 }
 
 // Build the UI texture view of the video data with textureId.
 class CameraPreview extends StatelessWidget {
-  final CameraController controller;
-
   const CameraPreview(this.controller);
 
+  final CameraController controller;
+
   @override
   Widget build(BuildContext context) {
     return controller.value.isInitialized
@@ -104,6 +104,20 @@ class CameraPreview extends StatelessWidget {
 
 /// The state of a [CameraController].
 class CameraValue {
+  const CameraValue({
+    this.isInitialized,
+    this.errorDescription,
+    this.previewSize,
+    this.isRecordingVideo,
+    this.isTakingPicture,
+  });
+
+  const CameraValue.uninitialized()
+      : this(
+            isInitialized: false,
+            isRecordingVideo: false,
+            isTakingPicture: false);
+
   /// True after [CameraController.initialize] has completed successfully.
   final bool isInitialized;
 
@@ -120,20 +134,6 @@ class CameraValue {
   /// Is `null` until  [isInitialized] is `true`.
   final Size previewSize;
 
-  const CameraValue({
-    this.isInitialized,
-    this.errorDescription,
-    this.previewSize,
-    this.isRecordingVideo,
-    this.isTakingPicture,
-  });
-
-  const CameraValue.uninitialized()
-      : this(
-            isInitialized: false,
-            isRecordingVideo: false,
-            isTakingPicture: false);
-
   /// Convenience getter for `previewSize.height / previewSize.width`.
   ///
   /// Can only be called when [initialize] is done.
@@ -176,6 +176,9 @@ class CameraValue {
 ///
 /// To show the camera preview on the screen use a [CameraPreview] widget.
 class CameraController extends ValueNotifier<CameraValue> {
+  CameraController(this.description, this.resolutionPreset)
+      : super(const CameraValue.uninitialized());
+
   final CameraDescription description;
   final ResolutionPreset resolutionPreset;
 
@@ -184,9 +187,6 @@ class CameraController extends ValueNotifier<CameraValue> {
   StreamSubscription<dynamic> _eventSubscription;
   Completer<Null> _creatingCompleter;
 
-  CameraController(this.description, this.resolutionPreset)
-      : super(const CameraValue.uninitialized());
-
   /// Initializes the camera on the device.
   ///
   /// Throws a [CameraException] if the initialization fails.