Stop running pub get at gclient sync time and fix build bugs

mojo/public/dart/third_party/barback/lib/src/errors.dart

Index: mojo/public/dart/third_party/barback/lib/src/errors.dart
diff --git a/mojo/public/dart/third_party/barback/lib/src/errors.dart b/mojo/public/dart/third_party/barback/lib/src/errors.dart
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+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library barback.errors;
+
+import 'package:stack_trace/stack_trace.dart';
+
+import 'asset/asset_id.dart';
+import 'transformer/wrapping_aggregate_transformer.dart';
+import 'utils.dart';
+
+/// Error thrown when an asset with [id] cannot be found.
+class AssetNotFoundException implements Exception {
+  final AssetId id;
+
+  AssetNotFoundException(this.id);
+
+  String toString() => "Could not find asset $id.";
+}
+
+/// Replaces any occurrences of [AggregateException] in [errors] with the list
+/// of errors it contains.
+Iterable<BarbackException> flattenAggregateExceptions(
+    Iterable<BarbackException> errors) {
+  return errors.expand((error) {
+    if (error is! AggregateException) return [error];
+    return error.errors;
+  });
+}
+
+/// The interface for exceptions from the barback graph or its transformers.
+///
+/// These exceptions are never produced by programming errors in barback.
+abstract class BarbackException implements Exception {
+  /// Takes a collection of [BarbackExceptions] and returns a single exception
+  /// that contains them all.
+  ///
+  /// If [errors] is empty, returns `null`. If it only has one error, that
+  /// error is returned. Otherwise, an [AggregateException] is returned.
+  static BarbackException aggregate(Iterable<BarbackException> errors) {
+    if (errors.isEmpty) return null;
+    if (errors.length == 1) return errors.single;
+    return new AggregateException(errors);
+  }
+}
+
+/// An error that wraps a collection of other [BarbackException]s.
+///
+/// It implicitly flattens any [AggregateException]s that occur in the list of
+/// exceptions it wraps.
+class AggregateException implements BarbackException {
+  final Set<BarbackException> errors;
+
+  AggregateException(Iterable<BarbackException> errors)
+      : errors = flattenAggregateExceptions(errors).toSet();
+
+  String toString() {
+    var buffer = new StringBuffer();
+    buffer.writeln("Multiple errors occurred:\n");
+
+    for (var error in errors) {
+      buffer.writeln(prefixLines(error.toString(),
+                                 prefix: "  ", firstPrefix: "- "));
+    }
+
+    return buffer.toString();
+  }
+}
+
+/// Error thrown when two or more transformers both output an asset with [id].
+class AssetCollisionException implements BarbackException {
+  /// All the transforms that output an asset with [id].
+  ///
+  /// If this only contains a single transform, that indicates that a
+  /// transformer produced an output that collides with a source asset or an
+  /// asset from a previous phase.
+  final Set<TransformInfo> transforms;
+  final AssetId id;
+
+  AssetCollisionException(Iterable<TransformInfo> transforms, this.id)
+      : transforms = new Set.from(transforms);
+
+  String toString() => "Transforms $transforms all emitted asset $id.";
+}
+
+/// Error thrown when a transformer requests an input [id] which cannot be
+/// found.
+class MissingInputException implements BarbackException {
+  /// The transform that requested [id].
+  final TransformInfo transform;
+  final AssetId id;
+
+  MissingInputException(this.transform, this.id);
+
+  String toString() => "Transform $transform tried to load missing input $id.";
+}
+
+/// Error thrown when a transformer outputs an asset to a different package than
+/// the primary input's.
+class InvalidOutputException implements BarbackException {
+  /// The transform that output the asset.
+  final TransformInfo transform;
+  final AssetId id;
+
+  InvalidOutputException(this.transform, this.id);
+
+  String toString() => "Transform $transform emitted $id, which wasn't in the "
+      "same package (${transform.primaryId.package}).";
+}
+
+/// Base class for an error that wraps another.
+abstract class _WrappedException implements BarbackException {
+  /// The wrapped exception.
+  final error;
+  final Chain stackTrace;
+
+  String get message => "$_message: ${getErrorMessage(error)}";
+
+  String get _message;
+
+  _WrappedException(error, StackTrace stackTrace)
+      : this.error = error,
+        this.stackTrace = _getChain(error, stackTrace);
+
+  String toString() {
+    var result = message;
+    if (stackTrace != null) result = "$result\n${stackTrace.terse}";
+    return result;
+  }
+}
+
+/// Returns the stack chain for [error] and [stackTrace].
+Chain _getChain(error, StackTrace stackTrace) {
+  if (error is Error && stackTrace == null) stackTrace = error.stackTrace;
+  if (stackTrace != null) return new Chain.forTrace(stackTrace);
+  return null;
+}
+
+/// Error wrapping an exception thrown by a transform.
+class TransformerException extends _WrappedException {
+  /// The transform that threw the exception.
+  final TransformInfo transform;
+
+  TransformerException(this.transform, error, StackTrace stackTrace)
+      : super(error, stackTrace);
+
+  String get _message => "Transform $transform threw error";
+}
+
+/// Error thrown when a source asset [id] fails to load.
+///
+/// This can be thrown either because the source asset was expected to exist and
+/// did not or because reading it failed somehow.
+class AssetLoadException extends _WrappedException {
+  final AssetId id;
+
+  AssetLoadException(this.id, error, [StackTrace stackTrace])
+      : super(error, stackTrace);
+
+  String get _message => "Failed to load source asset $id";
+}
+
+/// Information about a single transform in the barback graph.
+///
+/// Identifies a single transformation in the barback graph.
+///
+/// A transformation is uniquely identified by the ID of its primary input, and
+/// the transformer that is applied to it.
+class TransformInfo {
+  /// The transformer that's run for this transform.
+  ///
+  /// This may be a [Transformer] or a [WrappingAggregateTransformer]. It may
+  /// also return additional types in the future.
+  final transformer;
+
+  /// The id of this transform's primary asset.
+  final AssetId primaryId;
+
+  TransformInfo(transformer, this.primaryId)
+      : transformer = transformer is WrappingAggregateTransformer ?
+            transformer.transformer : transformer;
+
+  bool operator==(other) =>
+      other is TransformInfo &&
+      other.transformer == transformer &&
+      other.primaryId == primaryId;
+
+  int get hashCode => transformer.hashCode ^ primaryId.hashCode;
+
+  String toString() => "$transformer on $primaryId";
+}