Revert "[camera]fix a crash related to calling engine api in the back…

…ground thread (#4608)"

This reverts commit 3972212.

packages/camera/camera/CHANGELOG.md

@@ -1,8 +1,4 @@
-## NEXT
-
-* Fixed a crash in iOS when using image stream due to threading issue. 
-
-## 0.9.4+5
+##  0.9.4+5
 
 * Fixes bug where calling a method after the camera was closed resulted in a Java `IllegalStateException` exception.
 * Fixes integration tests.

packages/camera/camera/example/ios/Runner.xcodeproj/project.pbxproj

@@ -20,9 +20,6 @@
 		97C146FC1CF9000F007C117D /* Main.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 97C146FA1CF9000F007C117D /* Main.storyboard */; };
 		97C146FE1CF9000F007C117D /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = 97C146FD1CF9000F007C117D /* Assets.xcassets */; };
 		97C147011CF9000F007C117D /* LaunchScreen.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 97C146FF1CF9000F007C117D /* LaunchScreen.storyboard */; };
-		E0C6E2002770F01A00EA6AA3 /* ThreadSafeMethodChannelTests.m in Sources */ = {isa = PBXBuildFile; fileRef = E0C6E1FD2770F01A00EA6AA3 /* ThreadSafeMethodChannelTests.m */; };
-		E0C6E2012770F01A00EA6AA3 /* ThreadSafeTextureRegistryTests.m in Sources */ = {isa = PBXBuildFile; fileRef = E0C6E1FE2770F01A00EA6AA3 /* ThreadSafeTextureRegistryTests.m */; };
-		E0C6E2022770F01A00EA6AA3 /* ThreadSafeEventChannelTests.m in Sources */ = {isa = PBXBuildFile; fileRef = E0C6E1FF2770F01A00EA6AA3 /* ThreadSafeEventChannelTests.m */; };
 		E487C86026D686A10034AC92 /* CameraPreviewPauseTests.m in Sources */ = {isa = PBXBuildFile; fileRef = E487C85F26D686A10034AC92 /* CameraPreviewPauseTests.m */; };
 		F6EE622F2710A6FC00905E4A /* MockFLTThreadSafeFlutterResult.m in Sources */ = {isa = PBXBuildFile; fileRef = F6EE622E2710A6FC00905E4A /* MockFLTThreadSafeFlutterResult.m */; };
 /* End PBXBuildFile section */
@@ -77,9 +74,6 @@
 		97C147021CF9000F007C117D /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		9C5CC6CAD53AD388B2694F3A /* Pods-RunnerTests.debug.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-RunnerTests.debug.xcconfig"; path = "Target Support Files/Pods-RunnerTests/Pods-RunnerTests.debug.xcconfig"; sourceTree = "<group>"; };
 		A24F9E418BA48BCC7409B117 /* Pods-RunnerTests.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-RunnerTests.release.xcconfig"; path = "Target Support Files/Pods-RunnerTests/Pods-RunnerTests.release.xcconfig"; sourceTree = "<group>"; };
-		E0C6E1FD2770F01A00EA6AA3 /* ThreadSafeMethodChannelTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ThreadSafeMethodChannelTests.m; sourceTree = "<group>"; };
-		E0C6E1FE2770F01A00EA6AA3 /* ThreadSafeTextureRegistryTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ThreadSafeTextureRegistryTests.m; sourceTree = "<group>"; };
-		E0C6E1FF2770F01A00EA6AA3 /* ThreadSafeEventChannelTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ThreadSafeEventChannelTests.m; sourceTree = "<group>"; };
 		E487C85F26D686A10034AC92 /* CameraPreviewPauseTests.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = CameraPreviewPauseTests.m; sourceTree = "<group>"; };
 		F63F9EED27143B19002479BF /* MockFLTThreadSafeFlutterResult.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = MockFLTThreadSafeFlutterResult.h; sourceTree = "<group>"; };
 		F6EE622E2710A6FC00905E4A /* MockFLTThreadSafeFlutterResult.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = MockFLTThreadSafeFlutterResult.m; sourceTree = "<group>"; };
@@ -113,9 +107,6 @@
 				03BB766C2665316900CE5A93 /* Info.plist */,
 				033B94BD269C40A200B4DF97 /* CameraMethodChannelTests.m */,
 				03F6F8B126CBB4670024B8D3 /* ThreadSafeFlutterResultTests.m */,
-				E0C6E1FF2770F01A00EA6AA3 /* ThreadSafeEventChannelTests.m */,
-				E0C6E1FD2770F01A00EA6AA3 /* ThreadSafeMethodChannelTests.m */,
-				E0C6E1FE2770F01A00EA6AA3 /* ThreadSafeTextureRegistryTests.m */,
 				E487C85F26D686A10034AC92 /* CameraPreviewPauseTests.m */,
 				F6EE622E2710A6FC00905E4A /* MockFLTThreadSafeFlutterResult.m */,
 				F63F9EED27143B19002479BF /* MockFLTThreadSafeFlutterResult.h */,
@@ -248,7 +239,7 @@
 		97C146E61CF9000F007C117D /* Project object */ = {
 			isa = PBXProject;
 			attributes = {
-				LastUpgradeCheck = 1300;
+				LastUpgradeCheck = 1100;
 				ORGANIZATIONNAME = "The Flutter Authors";
 				TargetAttributes = {
 					03BB76672665316900CE5A93 = {
@@ -387,9 +378,6 @@
 				E487C86026D686A10034AC92 /* CameraPreviewPauseTests.m in Sources */,
 				F6EE622F2710A6FC00905E4A /* MockFLTThreadSafeFlutterResult.m in Sources */,
 				334733EA2668111C00DCC49E /* CameraOrientationTests.m in Sources */,
-				E0C6E2022770F01A00EA6AA3 /* ThreadSafeEventChannelTests.m in Sources */,
-				E0C6E2012770F01A00EA6AA3 /* ThreadSafeTextureRegistryTests.m in Sources */,
-				E0C6E2002770F01A00EA6AA3 /* ThreadSafeMethodChannelTests.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

packages/camera/camera/example/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1300"
+   LastUpgradeVersion = "1100"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"

packages/camera/camera/ios/Classes/CameraPlugin.m

@@ -10,10 +10,7 @@
 #import <CoreMotion/CoreMotion.h>
 #import <libkern/OSAtomic.h>
 #import <uuid/uuid.h>
-#import "FLTThreadSafeEventChannel.h"
 #import "FLTThreadSafeFlutterResult.h"
-#import "FLTThreadSafeMethodChannel.h"
-#import "FLTThreadSafeTextureRegistry.h"
 
 @interface FLTSavePhotoDelegate : NSObject <AVCapturePhotoCaptureDelegate>
 @property(readonly, nonatomic) NSString *path;
@@ -308,7 +305,7 @@ @interface FLTCam : NSObject <FlutterTexture,
 @property(nonatomic, copy) void (^onFrameAvailable)(void);
 @property BOOL enableAudio;
 @property(nonatomic) FLTImageStreamHandler *imageStreamHandler;
-@property(nonatomic) FLTThreadSafeMethodChannel *methodChannel;
+@property(nonatomic) FlutterMethodChannel *methodChannel;
 @property(readonly, nonatomic) AVCaptureSession *captureSession;
 @property(readonly, nonatomic) AVCaptureDevice *captureDevice;
 @property(readonly, nonatomic) AVCapturePhotoOutput *capturePhotoOutput API_AVAILABLE(ios(10));
@@ -1118,11 +1115,9 @@ - (void)startImageStreamWithMessenger:(NSObject<FlutterBinaryMessenger> *)messen
     FlutterEventChannel *eventChannel =
         [FlutterEventChannel eventChannelWithName:@"plugins.flutter.io/camera/imageStream"
                                   binaryMessenger:messenger];
-    FLTThreadSafeEventChannel *threadSafeEventChannel =
-        [[FLTThreadSafeEventChannel alloc] initWithEventChannel:eventChannel];
 
     _imageStreamHandler = [[FLTImageStreamHandler alloc] init];
-    [threadSafeEventChannel setStreamHandler:_imageStreamHandler];
+    [eventChannel setStreamHandler:_imageStreamHandler];
 
     _isStreamingImages = YES;
   } else {
@@ -1290,10 +1285,10 @@ - (void)setUpCaptureSessionForAudio {
 @end
 
 @interface CameraPlugin ()
-@property(readonly, nonatomic) FLTThreadSafeTextureRegistry *registry;
+@property(readonly, nonatomic) NSObject<FlutterTextureRegistry> *registry;
 @property(readonly, nonatomic) NSObject<FlutterBinaryMessenger> *messenger;
 @property(readonly, nonatomic) FLTCam *camera;
-@property(readonly, nonatomic) FLTThreadSafeMethodChannel *deviceEventMethodChannel;
+@property(readonly, nonatomic) FlutterMethodChannel *deviceEventMethodChannel;
 @end
 
 @implementation CameraPlugin {
@@ -1313,19 +1308,17 @@ - (instancetype)initWithRegistry:(NSObject<FlutterTextureRegistry> *)registry
                        messenger:(NSObject<FlutterBinaryMessenger> *)messenger {
   self = [super init];
   NSAssert(self, @"super init cannot be nil");
-  _registry = [[FLTThreadSafeTextureRegistry alloc] initWithTextureRegistry:registry];
+  _registry = registry;
   _messenger = messenger;
   [self initDeviceEventMethodChannel];
   [self startOrientationListener];
   return self;
 }
 
 - (void)initDeviceEventMethodChannel {
-  FlutterMethodChannel *methodChannel =
+  _deviceEventMethodChannel =
       [FlutterMethodChannel methodChannelWithName:@"flutter.io/cameraPlugin/device"
                                   binaryMessenger:_messenger];
-  _deviceEventMethodChannel =
-      [[FLTThreadSafeMethodChannel alloc] initWithMethodChannel:methodChannel];
 }
 
 - (void)startOrientationListener {
@@ -1424,7 +1417,7 @@ - (void)handleMethodCallAsync:(FlutterMethodCall *)call
       if (_camera) {
         [_camera close];
       }
-      int64_t textureId = [self.registry registerTextureSync:cam];
+      int64_t textureId = [self.registry registerTexture:cam];
       _camera = cam;
       [result sendSuccessWithData:@{
         @"cameraId" : @(textureId),
@@ -1453,10 +1446,8 @@ - (void)handleMethodCallAsync:(FlutterMethodCall *)call
           methodChannelWithName:[NSString stringWithFormat:@"flutter.io/cameraPlugin/camera%lu",
                                                            (unsigned long)cameraId]
                 binaryMessenger:_messenger];
-      FLTThreadSafeMethodChannel *threadSafeMethodChannel =
-          [[FLTThreadSafeMethodChannel alloc] initWithMethodChannel:methodChannel];
-      _camera.methodChannel = threadSafeMethodChannel;
-      [threadSafeMethodChannel
+      _camera.methodChannel = methodChannel;
+      [methodChannel
           invokeMethod:@"initialized"
              arguments:@{
                @"previewWidth" : @(_camera.previewSize.width),