Не уверен, как попал в ошибку компиляции:
Compiler message:
../../development/flutter/.pub-cache/hosted/pub.dartlang.org/http-0.12.2/lib/src/browser_client.dart:6:8: Error: Not found: 'dart:html'
import 'dart:html';
^
../../development/flutter/.pub-cache/hosted/pub.dartlang.org/http-0.12.2/lib/src/browser_client.dart:34:18: Error: 'HttpRequest' isn't a type.
final _xhrs = <HttpRequest>{};
^^^^^^^^^^^
../../development/flutter/.pub-cache/hosted/pub.dartlang.org/http-0.12.2/lib/src/browser_client.dart:58:34: Error: 'Blob' isn't a type.
var blob = xhr.response as Blob ?? Blob([]);
^^^^
../../development/flutter/.pub-cache/hosted/pub.dartlang.org/http-0.12.2/lib/src/browser_client.dart:46:15: Error: The method 'HttpRequest' isn't defined for the class 'BrowserClient'.
- 'BrowserClient' is from 'package:http/src/browser_client.dart' ('../../development/flutter/.pub-cache/hosted/pub.dartlang.org/http-0.12.2/lib/src/browser_client.dart').
Try correcting the name to the name of an existing method, or defining a method named 'HttpRequest'.
var xhr = HttpRequest();
^^^^^^^^^^^
../../development/flutter/.pub-cache/hosted/pub.dartlang.org/http-0.12.2/lib/src/browser_client.dart:58:42: Error: The method 'Blob' isn't defined for the class 'BrowserClient'.
- 'BrowserClient' is from 'package:http/src/browser_client.dart' ('../../development/flutter/.pub-cache/hosted/pub.dartlang.org/http-0.12.2/lib/src/browser_client.dart').
Try correcting the name to the name of an existing method, or defining a method named 'Blob'.
var blob = xhr.response as Blob ?? Blob([]);
^^^^
../../development/flutter/.pub-cache/hosted/pub.dartlang.org/http-0.12.2/lib/src/browser_client.dart:59:20: Error: The method 'FileReader' isn't defined for the class 'BrowserClient'.
- 'BrowserClient' is from 'package:http/src/browser_client.dart' ('../../development/flutter/.pub-cache/hosted/pub.dartlang.org/http-0.12.2/lib/src/browser_client.dart').
Try correcting the name to the name of an existing method, or defining a method named 'FileReader'.
var reader = FileReader();
^^^^^^^^^^