[iOS] Stop swizzling the |init| method of CameraController.

ios/chrome/browser/ui/qr_scanner/qr_scanner_view_controller_egtest.mm

Index: ios/chrome/browser/ui/qr_scanner/qr_scanner_view_controller_egtest.mm
diff --git a/ios/chrome/browser/ui/qr_scanner/qr_scanner_view_controller_egtest.mm b/ios/chrome/browser/ui/qr_scanner/qr_scanner_view_controller_egtest.mm
index 31aabe36b105c3c4bc0d41e5ab13b76fb8ad48ff..e656803c2828ff8200802b8503dd149912c09f07 100644
--- a/ios/chrome/browser/ui/qr_scanner/qr_scanner_view_controller_egtest.mm
+++ b/ios/chrome/browser/ui/qr_scanner/qr_scanner_view_controller_egtest.mm
@@ -396,13 +396,11 @@ - (NSString*)dialogTitleForState:(CameraState)state {
 - (void)swizzleCameraController:(id)cameraControllerMock {
   CameraController* (^swizzleCameraControllerBlock)(
       id<CameraControllerDelegate>) = ^(id<CameraControllerDelegate> delegate) {
-    // |initWithDelegate:| must return an object with a return count of 1
-    // because it is preceded by a call to |alloc|.
-    return [cameraControllerMock retain];
+    return cameraControllerMock;
   };
 
   camera_controller_swizzler_.reset(new ScopedBlockSwizzler(
-      [CameraController class], @selector(initWithDelegate:),
+      [CameraController class], @selector(cameraControllerWithDelegate:),
       swizzleCameraControllerBlock));
 }