Initial CL to create SDK directory (this will be done as a build step).

frog/reader.dart

Index: frog/reader.dart
===================================================================
--- frog/reader.dart	(revision 1719)
+++ frog/reader.dart	(working copy)
@@ -9,15 +9,30 @@
 class LibraryReader {
   Map _specialLibs;
   LibraryReader() {
-    _specialLibs = {
-      'dart:core': joinPaths(options.libDir, 'corelib.dart'),
-      'dart:coreimpl': joinPaths(options.libDir, 'corelib_impl.dart'),
-      'dart:html': joinPaths(options.libDir,
-          '../../client/html/release/html.dart'),
-      'dart:dom': joinPaths(options.libDir,
-          '../../client/dom/frog/frog_dom.dart'),
-      'dart:json': joinPaths(options.libDir, 'json.dart'),
-    };
+    if (options.config == 'dev') {
+      _specialLibs = {
+        'dart:core': joinPaths(options.libDir, 'corelib.dart'),
+        'dart:coreimpl': joinPaths(options.libDir, 'corelib_impl.dart'),
+        'dart:html': joinPaths(options.libDir,
+            '../../client/html/release/html.dart'),
+        'dart:dom': joinPaths(options.libDir,
+            '../../client/dom/frog/frog_dom.dart'),
+        'dart:json': joinPaths(options.libDir, 'json.dart'),
+      };
+    } else if (options.config == 'sdk') {
+      _specialLibs = {
+        'dart:core': joinPaths(options.libDir, 'corelib.dart'),
+        'dart:coreimpl': joinPaths(options.libDir, 'corelib_impl.dart'),
+        'dart:html': joinPaths(options.libDir,
+            '../../html/html.dart'),
+        'dart:dom': joinPaths(options.libDir,
+            '../../dom/frog/frog_dom.dart'),
+        'dart:json': joinPaths(options.libDir, 'json.dart'),
+      };
+    } else {
+      world.error('Invalid reader configuration $config', null);
+      throw('Invalid reader config');
+    }
   }
 
   SourceFile readFile(String fullname) {