Add a top-level node in the Files view to display the SDK libraries.

editor/tools/plugins/com.google.dart.tools.core/src/com/google/dart/tools/core/internal/model/SystemLibraryManagerProvider.java

Index: editor/tools/plugins/com.google.dart.tools.core/src/com/google/dart/tools/core/internal/model/SystemLibraryManagerProvider.java
===================================================================
--- editor/tools/plugins/com.google.dart.tools.core/src/com/google/dart/tools/core/internal/model/SystemLibraryManagerProvider.java	(revision 5473)
+++ editor/tools/plugins/com.google.dart.tools.core/src/com/google/dart/tools/core/internal/model/SystemLibraryManagerProvider.java	(working copy)
@@ -102,16 +102,11 @@
       if (VM_LIBRARY_MANAGER == null) {
         VM_LIBRARY_MANAGER = new EditorLibraryManager() {
 
-          @Override
-          protected String getPlatformName() {
-            return "runtime";
-          }
-
           /**
            * Return the SDK "lib" directory
            */
           @Override
-          File getLibrariesDir() {
+          public File getLibrariesDir() {
             DartSdk sdk = DartSdk.getInstance();
             if (sdk == null) {
               DartCore.logError("Missing SDK");
@@ -126,6 +121,11 @@
             }
             return librariesDir;
           }
+
+          @Override
+          protected String getPlatformName() {
+            return "runtime";
+          }
         };
       }
     }