Revert "Add Kernel Isolate"

runtime/bin/loader.h

Index: runtime/bin/loader.h
diff --git a/runtime/bin/loader.h b/runtime/bin/loader.h
index cc4912dda7011d81d163932caa9249d26fc7c6c8..2076be8b3133541462d24ba25d2a29324b25c45e 100644
--- a/runtime/bin/loader.h
+++ b/runtime/bin/loader.h
@@ -93,9 +93,6 @@ class Loader {
                    Dart_Handle url,
                    Dart_Handle library_url);
 
-  // Send a request from the tag handler to the kernel isolate.
-  void SendKernelRequest(Dart_LibraryTag tag, Dart_Handle url);
-
   /// Queue |message| and notify the loader that a message is available.
   void QueueMessage(Dart_CObject* message);