Remove unnecessary variables. (#86444)

packages/flutter_tools/lib/src/commands/attach.dart

@@ -411,8 +411,6 @@ known, it can be explicitly provided to attach via the command-line, e.g.
 
     final FlutterDevice flutterDevice = await FlutterDevice.create(
       device,
-      fileSystemRoots: stringsArg(FlutterOptions.kFileSystemRoot),
-      fileSystemScheme: stringArg(FlutterOptions.kFileSystemScheme),
       target: targetFile,
       targetModel: TargetModel(stringArg('target-model')),
       buildInfo: buildInfo,

packages/flutter_tools/lib/src/commands/run.dart

@@ -616,8 +616,6 @@ class RunCommand extends RunCommandBase {
       for (final Device device in devices)
         await FlutterDevice.create(
           device,
-          fileSystemRoots: fileSystemRoots,
-          fileSystemScheme: fileSystemScheme,
           experimentalFlags: expFlags,
           target: targetFile,
           buildInfo: buildInfo,

packages/flutter_tools/lib/src/compile.dart

@@ -542,7 +542,7 @@ class DefaultResidentCompiler implements ResidentCompiler {
     this.testCompilation = false,
     this.trackWidgetCreation = true,
     this.packagesPath,
-    this.fileSystemRoots = const <String>[],
+    List<String> fileSystemRoots = const <String>[],
     this.fileSystemScheme,
     this.initializeFromDill,
     this.targetModel = TargetModel.flutter,
@@ -560,7 +560,9 @@ class DefaultResidentCompiler implements ResidentCompiler {
        _platform = platform,
        dartDefines = dartDefines ?? const <String>[],
        // This is a URI, not a file path, so the forward slash is correct even on Windows.
-       sdkRoot = sdkRoot.endsWith('/') ? sdkRoot : '$sdkRoot/';
+       sdkRoot = sdkRoot.endsWith('/') ? sdkRoot : '$sdkRoot/',
+       // Make a copy, we might need to modify it later.
+       fileSystemRoots = List<String>.from(fileSystemRoots);
 
   final Logger _logger;
   final ProcessManager _processManager;

packages/flutter_tools/lib/src/resident_runner.dart

@@ -47,8 +47,6 @@ class FlutterDevice {
   FlutterDevice(
     this.device, {
     @required this.buildInfo,
-    this.fileSystemRoots,
-    this.fileSystemScheme,
     TargetModel targetModel = TargetModel.flutter,
     this.targetPlatform,
     ResidentCompiler generator,
@@ -62,8 +60,8 @@ class FlutterDevice {
          ),
          buildMode: buildInfo.mode,
          trackWidgetCreation: buildInfo.trackWidgetCreation,
-         fileSystemRoots: fileSystemRoots ?? <String>[],
+         fileSystemRoots: buildInfo.fileSystemRoots ?? <String>[],
-         fileSystemScheme: fileSystemScheme,
+         fileSystemScheme: buildInfo.fileSystemScheme,
          targetModel: targetModel,
          dartDefines: buildInfo.dartDefines,
          packagesPath: buildInfo.packagesPath,
@@ -81,8 +79,6 @@ class FlutterDevice {
     @required String target,
     @required BuildInfo buildInfo,
     @required Platform platform,
-    List<String> fileSystemRoots,
-    String fileSystemScheme,
     TargetModel targetModel = TargetModel.flutter,
     List<String> experimentalFlags,
     ResidentCompiler generator,
@@ -121,7 +117,7 @@ class FlutterDevice {
         globals.artifacts.getHostArtifact(HostArtifact.flutterWebSdk).path,
         buildMode: buildInfo.mode,
         trackWidgetCreation: buildInfo.trackWidgetCreation,
-        fileSystemRoots: fileSystemRoots ?? <String>[],
+        fileSystemRoots: buildInfo.fileSystemRoots ?? <String>[],
         // Override the filesystem scheme so that the frontend_server can find
         // the generated entrypoint code.
         fileSystemScheme: 'org-dartlang-app',
@@ -162,8 +158,8 @@ class FlutterDevice {
         ),
         buildMode: buildInfo.mode,
         trackWidgetCreation: buildInfo.trackWidgetCreation,
-        fileSystemRoots: fileSystemRoots,
+        fileSystemRoots: buildInfo.fileSystemRoots,
-        fileSystemScheme: fileSystemScheme,
+        fileSystemScheme: buildInfo.fileSystemScheme,
         targetModel: targetModel,
         dartDefines: buildInfo.dartDefines,
         extraFrontEndOptions: extraFrontEndOptions,
@@ -183,8 +179,6 @@ class FlutterDevice {
 
     return FlutterDevice(
       device,
-      fileSystemRoots: fileSystemRoots,
-      fileSystemScheme:fileSystemScheme,
       targetModel: targetModel,
       targetPlatform: targetPlatform,
       generator: generator,
@@ -204,8 +198,6 @@ class FlutterDevice {
   FlutterVmService vmService;
   DevFS devFS;
   ApplicationPackage package;
-  List<String> fileSystemRoots;
-  String fileSystemScheme;
   StreamSubscription<String> _loggingSubscription;
   bool _isListeningForObservatoryUri;
 

packages/flutter_tools/test/commands.shard/hermetic/attach_test.dart

@@ -197,8 +197,8 @@ void main() {
         // output dill, filesystem scheme, and filesystem root.
         final FlutterDevice flutterDevice = hotRunnerFactory.devices.first;
 
-        expect(flutterDevice.fileSystemScheme, filesystemScheme);
+        expect(flutterDevice.buildInfo.fileSystemScheme, filesystemScheme);
-        expect(flutterDevice.fileSystemRoots, const <String>[filesystemRoot]);
+        expect(flutterDevice.buildInfo.fileSystemRoots, const <String>[filesystemRoot]);
       }, overrides: <Type, Generator>{
         FileSystem: () => testFileSystem,
         ProcessManager: () => FakeProcessManager.any(),