Add browser-compatible version.

lib/src/browser/loader.dart

Index: lib/src/browser/loader.dart
diff --git a/lib/src/loader.dart b/lib/src/browser/loader.dart
similarity index 62%
copy from lib/src/loader.dart
copy to lib/src/browser/loader.dart
index b6b4e678247bacd4a2a519afd6767de07fb27407..2c89c504b12d49035656a38745c2346422ff3e81 100644
--- a/lib/src/loader.dart
+++ b/lib/src/browser/loader.dart
@@ -5,7 +5,8 @@
 import "dart:async" show Future, Stream;
 import "dart:convert" show Encoding;
 import "dart:isolate" show Isolate;
-import "io.dart" as io;  // TODO: make this import configuration dependent.
+
+import "html_io.dart" as io;
 
 /// Resource loading strategy.
 ///
@@ -24,7 +25,7 @@ abstract class ResourceLoader {
   /// (For example, file: URIs are not supported in the browser).
   /// Relative URI references are accepted - they are resolved against
   /// [Uri.base] before being loaded.
-  static const ResourceLoader defaultLoader = const PackageLoader();
+  static ResourceLoader get defaultLoader => const DefaultLoader();
 
   /// Reads the file located by [uri] as a stream of bytes.
   Stream<List<int>> openRead(Uri uri);
@@ -44,12 +45,13 @@ abstract class ResourceLoader {
   Future<String> readAsString(Uri uri, { Encoding encoding });
 }
 
-/// Default implementation of [ResourceLoader].
+/// Default implementation of [ResourceLoader]..
 ///
 /// Uses the system's available loading functionality to implement the
 /// loading functions.
 ///
-/// Supports `http:`, `https:`, `file:` and `data:` URIs.
+/// Supports as many of `http:`, `https:`, `file:` and `data:` URIs as
+/// possible.
 class DefaultLoader implements ResourceLoader {
   const DefaultLoader();
 
@@ -60,33 +62,3 @@ class DefaultLoader implements ResourceLoader {
   Future<String> readAsString(Uri uri, { Encoding encoding }) =>
       io.readAsString(uri, encoding);
 }
-
-
-/// Implementation of [ResourceLoader] that accepts relative and package: URIs.
-///
-/// Like [DefaultLoader] except that it resolves package URIs and relative
-/// URI references as well.
-///
-/// This class may be useful when you don't want to bother creating a [Resource]
-/// object, and just want to load a resource directly.
-class PackageLoader implements ResourceLoader {
-  const PackageLoader();
-
-  Stream<List<int>> openRead(Uri uri) async* {
-    yield* io.readAsStream(await resolveUri(uri));
-  }
-
-  Future<List<int>> readAsBytes(Uri uri) async =>
-      io.readAsBytes(await resolveUri(uri));
-
-  Future<String> readAsString(Uri uri, { Encoding encoding }) async =>
-      io.readAsString(await resolveUri(uri), encoding);
-}
-
-/// Helper function for resolving to a non-relative, non-package URI.
-Future<Uri> resolveUri(Uri uri) async {
-  if (uri.scheme == "package") {
-    return Isolate.resolvePackageUri(uri);
-  }
-  return Uri.base.resolveUri(uri);
-}