- Add dart:json, dart:uri and dart:utf8 to the known and builtin libraries.

bin/gen_snapshot.cc

Index: bin/gen_snapshot.cc
===================================================================
--- bin/gen_snapshot.cc	(revision 4317)
+++ bin/gen_snapshot.cc	(working copy)
@@ -204,10 +204,9 @@
                           BuiltinLibraryTagHandler,
                           import_map);
   } else {
-    ASSERT(id == Builtin::kIOLibrary);
-    // Load the dart:io library to make it available in the snapshot
+    // Load the builtin library to make it available in the snapshot
     // for importing.
-    lib = Builtin::LoadLibrary(Builtin::kIOLibrary);
+    lib = Builtin::LoadLibrary(id);
   }
   if (!Dart_IsError(lib)) {
     Builtin::SetupLibrary(lib, id);
@@ -287,6 +286,12 @@
     VerifyLoaded(library);
     library = LoadGenericSnapshotCreationScript(Builtin::kIOLibrary);
     VerifyLoaded(library);
+    library = LoadGenericSnapshotCreationScript(Builtin::kJsonLibrary);
+    VerifyLoaded(library);
+    library = LoadGenericSnapshotCreationScript(Builtin::kUriLibrary);
+    VerifyLoaded(library);
+    library = LoadGenericSnapshotCreationScript(Builtin::kUtf8Library);
+    VerifyLoaded(library);
   }
 
   uint8_t* buffer = NULL;