Remove unused --packages argument to gen_snapshot. (#28334)

This command line argument has already been removed in the main
Dart repository, so building flutter with the latest dart fails.

This time, also update the tests to avoid the checks for a package
path on snapshot generation.

packages/flutter_tools/lib/src/base/build.dart

@@ -46,13 +46,11 @@ class GenSnapshot {
 
   Future<int> run({
     @required SnapshotType snapshotType,
-    @required String packagesPath,
     IOSArch iosArch,
     Iterable<String> additionalArgs = const <String>[],
   }) {
     final List<String> args = <String>[
       '--causal_async_stacks',
-      '--packages=$packagesPath',
     ]..addAll(additionalArgs);
 
     final String snapshotterPath = getSnapshotterPath(snapshotType);
@@ -193,7 +191,6 @@ class AOTSnapshotter {
     final SnapshotType snapshotType = SnapshotType(platform, buildMode);
     final int genSnapshotExitCode = await genSnapshot.run(
       snapshotType: snapshotType,
-      packagesPath: packageMap.packagesPath,
       additionalArgs: genSnapshotArgs,
       iosArch: iosArch,
     );
@@ -537,7 +534,6 @@ class JITSnapshotter {
     final SnapshotType snapshotType = SnapshotType(platform, buildMode);
     final int genSnapshotExitCode = await genSnapshot.run(
       snapshotType: snapshotType,
-      packagesPath: packagesPath,
       additionalArgs: genSnapshotArgs,
     );
     if (genSnapshotExitCode != 0) {

packages/flutter_tools/test/base/build_test.dart

@@ -35,7 +35,6 @@ class _FakeGenSnapshot implements GenSnapshot {
   Map<String, String> outputs = <String, String>{};
   int _callCount = 0;
   SnapshotType _snapshotType;
-  String _packagesPath;
   String _depfilePath;
   List<String> _additionalArgs;
 
@@ -43,8 +42,6 @@ class _FakeGenSnapshot implements GenSnapshot {
 
   SnapshotType get snapshotType => _snapshotType;
 
-  String get packagesPath => _packagesPath;
-
   String get depfilePath => _depfilePath;
 
   List<String> get additionalArgs => _additionalArgs;
@@ -52,14 +49,12 @@ class _FakeGenSnapshot implements GenSnapshot {
   @override
   Future<int> run({
     SnapshotType snapshotType,
-    String packagesPath,
     String depfilePath,
     IOSArch iosArch,
     Iterable<String> additionalArgs = const <String>[],
   }) async {
     _callCount += 1;
     _snapshotType = snapshotType;
-    _packagesPath = packagesPath;
     _depfilePath = depfilePath;
     _additionalArgs = additionalArgs.toList();
 
@@ -190,7 +185,6 @@ void main() {
       expect(genSnapshot.callCount, 1);
       expect(genSnapshot.snapshotType.platform, TargetPlatform.ios);
       expect(genSnapshot.snapshotType.mode, BuildMode.profile);
-      expect(genSnapshot.packagesPath, '.packages');
       expect(genSnapshot.additionalArgs, <String>[
         '--deterministic',
         '--snapshot_kind=app-aot-assembly',
@@ -229,7 +223,6 @@ void main() {
       expect(genSnapshot.callCount, 1);
       expect(genSnapshot.snapshotType.platform, TargetPlatform.ios);
       expect(genSnapshot.snapshotType.mode, BuildMode.profile);
-      expect(genSnapshot.packagesPath, '.packages');
       expect(genSnapshot.additionalArgs, <String>[
         '--deterministic',
         '--snapshot_kind=app-aot-assembly',
@@ -268,7 +261,6 @@ void main() {
       expect(genSnapshot.callCount, 1);
       expect(genSnapshot.snapshotType.platform, TargetPlatform.android_arm);
       expect(genSnapshot.snapshotType.mode, BuildMode.profile);
-      expect(genSnapshot.packagesPath, '.packages');
       expect(genSnapshot.additionalArgs, <String>[
         '--deterministic',
         '--snapshot_kind=app-aot-blobs',
@@ -312,7 +304,6 @@ void main() {
       expect(genSnapshot.callCount, 1);
       expect(genSnapshot.snapshotType.platform, TargetPlatform.android_arm64);
       expect(genSnapshot.snapshotType.mode, BuildMode.profile);
-      expect(genSnapshot.packagesPath, '.packages');
       expect(genSnapshot.additionalArgs, <String>[
         '--deterministic',
         '--snapshot_kind=app-aot-blobs',
@@ -352,7 +343,6 @@ void main() {
       expect(genSnapshot.callCount, 1);
       expect(genSnapshot.snapshotType.platform, TargetPlatform.ios);
       expect(genSnapshot.snapshotType.mode, BuildMode.release);
-      expect(genSnapshot.packagesPath, '.packages');
       expect(genSnapshot.additionalArgs, <String>[
         '--deterministic',
         '--snapshot_kind=app-aot-assembly',
@@ -391,7 +381,6 @@ void main() {
       expect(genSnapshot.callCount, 1);
       expect(genSnapshot.snapshotType.platform, TargetPlatform.ios);
       expect(genSnapshot.snapshotType.mode, BuildMode.release);
-      expect(genSnapshot.packagesPath, '.packages');
       expect(genSnapshot.additionalArgs, <String>[
         '--deterministic',
         '--snapshot_kind=app-aot-assembly',
@@ -448,7 +437,6 @@ void main() {
       expect(genSnapshot.callCount, 1);
       expect(genSnapshot.snapshotType.platform, TargetPlatform.android_arm);
       expect(genSnapshot.snapshotType.mode, BuildMode.release);
-      expect(genSnapshot.packagesPath, '.packages');
       expect(genSnapshot.additionalArgs, <String>[
         '--deterministic',
         '--snapshot_kind=app-aot-blobs',
@@ -492,7 +480,6 @@ void main() {
       expect(genSnapshot.callCount, 1);
       expect(genSnapshot.snapshotType.platform, TargetPlatform.android_arm64);
       expect(genSnapshot.snapshotType.mode, BuildMode.release);
-      expect(genSnapshot.packagesPath, '.packages');
       expect(genSnapshot.additionalArgs, <String>[
         '--deterministic',
         '--snapshot_kind=app-aot-blobs',
@@ -581,7 +568,6 @@ void main() {
       expect(genSnapshot.callCount, 1);
       expect(genSnapshot.snapshotType.platform, TargetPlatform.android_arm);
       expect(genSnapshot.snapshotType.mode, BuildMode.debug);
-      expect(genSnapshot.packagesPath, '.packages');
       expect(genSnapshot.additionalArgs, <String>[
         '--deterministic',
         '--enable_asserts',
@@ -622,7 +608,6 @@ void main() {
       expect(genSnapshot.callCount, 1);
       expect(genSnapshot.snapshotType.platform, TargetPlatform.android_arm64);
       expect(genSnapshot.snapshotType.mode, BuildMode.debug);
-      expect(genSnapshot.packagesPath, '.packages');
       expect(genSnapshot.additionalArgs, <String>[
         '--deterministic',
         '--enable_asserts',
@@ -674,7 +659,6 @@ void main() {
       expect(genSnapshot.callCount, 1);
       expect(genSnapshot.snapshotType.platform, TargetPlatform.android_arm);
       expect(genSnapshot.snapshotType.mode, BuildMode.profile);
-      expect(genSnapshot.packagesPath, '.packages');
       expect(genSnapshot.additionalArgs, <String>[
         '--deterministic',
         '--snapshot_kind=app-jit',
@@ -714,7 +698,6 @@ void main() {
       expect(genSnapshot.callCount, 1);
       expect(genSnapshot.snapshotType.platform, TargetPlatform.android_arm64);
       expect(genSnapshot.snapshotType.mode, BuildMode.profile);
-      expect(genSnapshot.packagesPath, '.packages');
       expect(genSnapshot.additionalArgs, <String>[
         '--deterministic',
         '--snapshot_kind=app-jit',
@@ -765,7 +748,6 @@ void main() {
       expect(genSnapshot.callCount, 1);
       expect(genSnapshot.snapshotType.platform, TargetPlatform.android_arm);
       expect(genSnapshot.snapshotType.mode, BuildMode.release);
-      expect(genSnapshot.packagesPath, '.packages');
       expect(genSnapshot.additionalArgs, <String>[
         '--deterministic',
         '--snapshot_kind=app-jit',
@@ -805,7 +787,6 @@ void main() {
       expect(genSnapshot.callCount, 1);
       expect(genSnapshot.snapshotType.platform, TargetPlatform.android_arm64);
       expect(genSnapshot.snapshotType.mode, BuildMode.release);
-      expect(genSnapshot.packagesPath, '.packages');
       expect(genSnapshot.additionalArgs, <String>[
         '--deterministic',
         '--snapshot_kind=app-jit',
@@ -860,7 +841,6 @@ void main() {
       expect(genSnapshot.callCount, 1);
       expect(genSnapshot.snapshotType.platform, TargetPlatform.android_arm);
       expect(genSnapshot.snapshotType.mode, BuildMode.release);
-      expect(genSnapshot.packagesPath, '.packages');
       expect(genSnapshot.additionalArgs, <String>[
         '--deterministic',
         '--snapshot_kind=app-jit',
@@ -917,7 +897,6 @@ void main() {
       expect(genSnapshot.callCount, 1);
       expect(genSnapshot.snapshotType.platform, TargetPlatform.android_arm);
       expect(genSnapshot.snapshotType.mode, BuildMode.release);
-      expect(genSnapshot.packagesPath, '.packages');
       expect(genSnapshot.additionalArgs, <String>[
         '--deterministic',
         '--snapshot_kind=app-jit',