Fix observatory crash on most operations due to isolate not runnable

Source/bindings/core/dart/DartApplicationLoader.cpp

Index: Source/bindings/core/dart/DartApplicationLoader.cpp
diff --git a/Source/bindings/core/dart/DartApplicationLoader.cpp b/Source/bindings/core/dart/DartApplicationLoader.cpp
index 51104cf3f1fcaeaab178bf07727f820ff6c6010b..79a8546f3fcb276b2609775b879b50aa241b26ad 100644
--- a/Source/bindings/core/dart/DartApplicationLoader.cpp
+++ b/Source/bindings/core/dart/DartApplicationLoader.cpp
@@ -440,7 +440,7 @@ void DartApplicationLoader::callEntryPoint()
             // TODO(jacobr): do we need to cleanup the dartDOMData for the isolate?
             Dart_ShutdownIsolate();
             free(script_snapshot);
-
+            Dart_IsolateMakeRunnable(applicationIsolate);
             Dart_EnterIsolate(applicationIsolate);
         }