Merge pull request flutter#9 from holykou/master

Video stream freeze fix.

Author: luigi-agosti

packages/camera/ios/Classes/CameraPlugin.m

@@ -424,6 +424,9 @@ - (instancetype)initWithRegistry:(NSObject<FlutterTextureRegistry> *)registry
 
 - (void)handleMethodCall:(FlutterMethodCall *)call result:(FlutterResult)result {
   if ([@"init" isEqualToString:call.method]) {
+      if (_camera) {
+          [_camera close];
+      }
     result(nil);
   } else if ([@"availableCameras" isEqualToString:call.method]) {
     AVCaptureDeviceDiscoverySession *discoverySession = [AVCaptureDeviceDiscoverySession
@@ -462,6 +465,9 @@ - (void)handleMethodCall:(FlutterMethodCall *)call result:(FlutterResult)result
     if (error) {
       result([error flutterError]);
     } else {
+        if (_camera) {
+            [_camera close];
+        }
       int64_t textureId = [_registry registerTexture:cam];
       _camera = cam;
       cam.onFrameAvailable = ^{