Revert of Allow headless TabSocket in isolated worlds & remove obsolete logic

third_party/WebKit/public/platform/WebIsolatedWorldIds.h

Index: third_party/WebKit/public/platform/WebIsolatedWorldIds.h
diff --git a/third_party/WebKit/public/platform/WebIsolatedWorldIds.h b/third_party/WebKit/public/platform/WebIsolatedWorldIds.h
deleted file mode 100644
index 73f0edb441b5887027f0591d8016aa6b3dc8a372..0000000000000000000000000000000000000000
--- a/third_party/WebKit/public/platform/WebIsolatedWorldIds.h
+++ /dev/null
@@ -1,21 +0,0 @@
-// Copyright 2017 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef WebIsolatedWorldIds_h
-#define WebIsolatedWorldIds_h
-
-namespace blink {
-
-enum IsolatedWorldId {
-  // Embedder isolated worlds can use IDs in [1, 1<<29).
-  kEmbedderWorldIdLimit = (1 << 29),
-  kDocumentXMLTreeViewerWorldId,
-  kDevToolsFirstIsolatedWorldId,
-  kDevToolsLastIsolatedWorldId = kDevToolsFirstIsolatedWorldId + 100,
-  kIsolatedWorldIdLimit,
-};
-
-}  // namespace blink
-
-#endif  // WebIsolatedWorldIds_h