diff --git a/packages/flutter_tools/lib/src/asset.dart b/packages/flutter_tools/lib/src/asset.dart
index d2a38bf..b5514e5 100644
--- a/packages/flutter_tools/lib/src/asset.dart
+++ b/packages/flutter_tools/lib/src/asset.dart
@@ -9,6 +9,7 @@
 
 import 'base/context.dart';
 import 'base/file_system.dart';
+import 'base/platform.dart';
 import 'build_info.dart';
 import 'cache.dart';
 import 'dart/package_map.dart';
@@ -365,9 +366,19 @@
   return new DevFSStringContent(combinedLicenses);
 }
 
+int _byBasename(_Asset a, _Asset b) {
+  return a.assetFile.basename.compareTo(b.assetFile.basename);
+}
+
 DevFSContent _createAssetManifest(Map<_Asset, List<_Asset>> assetVariants) {
   final Map<String, List<String>> jsonObject = <String, List<String>>{};
-  for (_Asset main in assetVariants.keys) {
+
+  // necessary for making unit tests deterministic
+  final List<_Asset> sortedKeys = assetVariants
+      .keys.toList()
+    ..sort(_byBasename);
+
+  for (_Asset main in sortedKeys) {
     final List<String> variants = <String>[];
     for (_Asset variant in assetVariants[main])
       variants.add(variant.entryUri.path);
@@ -485,6 +496,27 @@
 /// map of assets to asset variants.
 ///
 /// Returns null on missing assets.
+///
+/// Given package: 'test_package' and an assets directory like this:
+///
+/// assets/foo
+/// assets/var1/foo
+/// assets/var2/foo
+/// assets/bar
+///
+/// returns
+/// {
+///   asset: packages/test_package/assets/foo: [
+///     asset: packages/test_package/assets/foo,
+///     asset: packages/test_package/assets/var1/foo,
+///     asset: packages/test_package/assets/var2/foo,
+///   ],
+///   asset: packages/test_package/assets/bar: [
+///     asset: packages/test_package/assets/bar,
+///   ],
+/// }
+///
+
 Map<_Asset, List<_Asset>> _parseAssets(
   PackageMap packageMap,
   FlutterManifest flutterManifest,
@@ -496,27 +528,15 @@
 
   final _AssetDirectoryCache cache = new _AssetDirectoryCache(excludeDirs);
   for (Uri assetUri in flutterManifest.assets) {
-    final _Asset asset = _resolveAsset(
-      packageMap,
-      assetBase,
-      assetUri,
-      packageName,
-    );
-    final List<_Asset> variants = <_Asset>[];
-    for (String path in cache.variantsFor(asset.assetFile.path)) {
-      final String relativePath = fs.path.relative(path, from: asset.baseDir);
-      final Uri relativeUri = fs.path.toUri(relativePath);
-      final Uri entryUri = asset.symbolicPrefixUri == null
-          ? relativeUri
-          : asset.symbolicPrefixUri.resolveUri(relativeUri);
-      variants.add(new _Asset(
-        baseDir: asset.baseDir,
-        entryUri: entryUri,
-        relativeUri: relativeUri,
-      ));
+    if (assetUri.toString().endsWith('/')) {
+      _parseAssetsFromFolder(packageMap, flutterManifest, assetBase,
+          cache, result, assetUri,
+          excludeDirs: excludeDirs, packageName: packageName);
+    } else {
+      _parseAssetFromFile(packageMap, flutterManifest, assetBase,
+          cache, result, assetUri,
+          excludeDirs: excludeDirs, packageName: packageName);
     }
-
-    result[asset] = variants;
   }
 
   // Add assets referenced in the fonts section of the manifest.
@@ -540,6 +560,72 @@
   return result;
 }
 
+void _parseAssetsFromFolder(PackageMap packageMap,
+  FlutterManifest flutterManifest,
+  String assetBase,
+  _AssetDirectoryCache cache,
+  Map<_Asset, List<_Asset>> result,
+  Uri assetUri, {
+  List<String> excludeDirs: const <String>[],
+  String packageName
+}) {
+  final String directoryPath = fs.path.join(
+      assetBase, assetUri.toFilePath(windows: platform.isWindows));
+
+  if (!fs.directory(directoryPath).existsSync()) {
+    printError('Error: unable to find directory entry in pubspec.yaml: $directoryPath');
+    return;
+  }
+
+  final List<FileSystemEntity> lister = fs.directory(directoryPath).listSync();
+
+  for (FileSystemEntity entity in lister) {
+    if (entity is File) {
+      final String relativePath = fs.path.relative(entity.path, from: assetBase);
+
+      final Uri uri = new Uri.file(relativePath, windows: platform.isWindows);
+
+      _parseAssetFromFile(packageMap, flutterManifest, assetBase, cache, result,
+          uri, packageName: packageName);
+    }
+  }
+}
+
+void _parseAssetFromFile(PackageMap packageMap,
+  FlutterManifest flutterManifest,
+  String assetBase,
+  _AssetDirectoryCache cache,
+  Map<_Asset, List<_Asset>> result,
+  Uri assetUri, {
+  List<String> excludeDirs: const <String>[],
+  String packageName
+}) {
+  final _Asset asset = _resolveAsset(
+    packageMap,
+    assetBase,
+    assetUri,
+    packageName,
+  );
+  final List<_Asset> variants = <_Asset>[];
+  for (String path in cache.variantsFor(asset.assetFile.path)) {
+    final String relativePath = fs.path.relative(path, from: asset.baseDir);
+    final Uri relativeUri = fs.path.toUri(relativePath);
+    final Uri entryUri = asset.symbolicPrefixUri == null
+        ? relativeUri
+        : asset.symbolicPrefixUri.resolveUri(relativeUri);
+
+    variants.add(
+      new _Asset(
+        baseDir: asset.baseDir,
+        entryUri: entryUri,
+        relativeUri: relativeUri,
+        )
+    );
+  }
+
+  result[asset] = variants;
+}
+
 _Asset _resolveAsset(
   PackageMap packageMap,
   String assetsBaseDir,
diff --git a/packages/flutter_tools/lib/src/dart/package_map.dart b/packages/flutter_tools/lib/src/dart/package_map.dart
index dd04a11..c1b7bfc 100644
--- a/packages/flutter_tools/lib/src/dart/package_map.dart
+++ b/packages/flutter_tools/lib/src/dart/package_map.dart
@@ -5,12 +5,14 @@
 import 'package:package_config/packages_file.dart' as packages_file;
 
 import '../base/file_system.dart';
+import '../base/platform.dart';
 
 const String kPackagesFileName = '.packages';
 
 Map<String, Uri> _parse(String packagesPath) {
   final List<int> source = fs.file(packagesPath).readAsBytesSync();
-  return packages_file.parse(source, new Uri.file(packagesPath));
+  return packages_file.parse(source,
+      new Uri.file(packagesPath, windows: platform.isWindows));
 }
 
 class PackageMap {
diff --git a/packages/flutter_tools/lib/src/flutter_manifest.dart b/packages/flutter_tools/lib/src/flutter_manifest.dart
index 1731ceb..0c26c47 100644
--- a/packages/flutter_tools/lib/src/flutter_manifest.dart
+++ b/packages/flutter_tools/lib/src/flutter_manifest.dart
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'dart:async';
+import 'dart:convert' as convert;
 
 import 'package:json_schema/json_schema.dart';
 import 'package:meta/meta.dart';
@@ -151,13 +152,27 @@
   String toString() => '$runtimeType(asset: ${assetUri.path}, weight; $weight, style: $style)';
 }
 
-Future<bool> _validate(Object manifest) async {
-  final String schemaPath = fs.path.join(
+@visibleForTesting
+String buildSchemaDir(FileSystem fs) {
+  return fs.path.join(
     fs.path.absolute(Cache.flutterRoot), 'packages', 'flutter_tools', 'schema',
+  );
+}
+
+@visibleForTesting
+String buildSchemaPath(FileSystem fs) {
+  return fs.path.join(
+    buildSchemaDir(fs),
     'pubspec_yaml.json',
   );
-  final Schema schema = await Schema.createSchemaFromUrl(fs.path.toUri(schemaPath).toString());
+}
 
+Future<bool> _validate(Object manifest) async {
+  final String schemaPath = buildSchemaPath(fs);
+
+  final String schemaData = fs.file(schemaPath).readAsStringSync();
+  final Schema schema = await Schema.createSchema(
+      convert.json.decode(schemaData));
   final Validator validator = new Validator(schema);
   if (validator.validate(manifest)) {
     return true;