Removed Isolate::EnterDefaultIsolate.

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index 62665f98ab2cab13ab8f6ce46426cc6fdb55fe64..afebdf1381aa378e35fceaf2b3821b5465787ad7 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -570,12 +570,6 @@ class Isolate {
 
   static Thread::LocalStorageKey per_isolate_thread_data_key();
 
-  // If a client attempts to create a Locker without specifying an isolate,
-  // we assume that the client is using legacy behavior. Set up the current
-  // thread to be inside the implicit isolate (or fail a check if we have
-  // switched to non-legacy behavior).
-  static void EnterDefaultIsolate();
-
   // Mutex for serializing access to break control structures.
   RecursiveMutex* break_access() { return &break_access_; }