[flutter_tools] remove iOS screenshot on failure functionality (#68650)

* [flutter_tools] remove iOS screenshot on failure functionality

* remove all screenshot code

dev/devicelab/lib/framework/utils.dart

@@ -282,7 +282,6 @@ Future<Process> startProcess(
       + (environment != null ? ' with environment $environment' : ''));
   final Map<String, String> newEnvironment = Map<String, String>.from(environment ?? <String, String>{});
   newEnvironment['BOT'] = isBot ? 'true' : 'false';
-  newEnvironment['FLUTTER_IOS_SCREENSHOT_ON_CONNECTION_FAILURE'] = 'true';
   final Process process = await _processManager.start(
     <String>[executable, ...arguments],
     environment: newEnvironment,

packages/flutter_tools/lib/src/ios/devices.dart

@@ -11,7 +11,6 @@ import 'package:vm_service/vm_service.dart' as vm_service;
 
 import '../application_package.dart';
 import '../base/common.dart';
-import '../base/error_handling_io.dart';
 import '../base/file_system.dart';
 import '../base/io.dart';
 import '../base/logger.dart';
@@ -440,7 +439,6 @@ class IOSDevice extends Device {
         installationResult = await iosDeployDebugger.launchAndAttach() ? 0 : 1;
       }
       if (installationResult != 0) {
-        await _screenshotOnFailure();
         _logger.printError('Could not run ${bundle.path} on $id.');
         _logger.printError('Try launching Xcode and selecting "Product > Run" to fix the problem:');
         _logger.printError('  open ios/Runner.xcworkspace');
@@ -470,7 +468,6 @@ class IOSDevice extends Device {
         packageName: FlutterProject.current().manifest.appName,
       );
       if (localUri == null) {
-        await _screenshotOnFailure();
         iosDeployDebugger?.detach();
         return LaunchResult.failed();
       }
@@ -559,23 +556,6 @@ class IOSDevice extends Device {
     });
     await _portForwarder?.dispose();
   }
-
-  Future<void> _screenshotOnFailure() async {
-    final bool screenshotOnConnectionFailure = _platform
-      .environment['FLUTTER_IOS_SCREENSHOT_ON_CONNECTION_FAILURE'] == 'true';
-    if (!screenshotOnConnectionFailure) {
-      return;
-    }
-    final File file = _fileSystem.file('test_screenshot.png');
-    try {
-      await takeScreenshot(file);
-      _logger.printStatus('BASE64 SCREENSHOT:${base64.encode(file.readAsBytesSync())}');
-    } on Exception {
-      _logger.printError('Failed to take screenshot');
-    } finally {
-      ErrorHandlingFileSystem.deleteIfExists(file);
-    }
-  }
 }
 
 /// Decodes a vis-encoded syslog string to a UTF-8 representation.

packages/flutter_tools/tool/screenshot_decoder.dart

-// Copyright 2014 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// @dart = 2.9
-
-import 'dart:convert';
-import 'dart:io';
-
-/// decodes a base64 screenshot stored in the devicelab.
-///
-/// Usage dart tool/screenshot_decoder.dart path/to/log_file
-void main(List<String> arguments) {
-  int screenshot = 0;
-  final String logFile = arguments.first;
-  for (final String line in File(logFile).readAsLinesSync()) {
-    if (!line.contains('BASE64 SCREENSHOT:')) {
-      continue;
-    }
-    final String message = line.split('BASE64 SCREENSHOT:')[1];
-    final List<int> bytes = base64.decode(message);
-    File('flutter_screenshot_$screenshot.png').writeAsBytesSync(bytes);
-    screenshot += 1;
-  }
-}