[Reland] Allow headless TabSocket in isolated worlds & remove obsolete logic

content/public/common/bindings_policy.h

 // Copyright (c) 2012 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 CONTENT_PUBLIC_COMMON_BINDINGS_POLICY_H_
 #define CONTENT_PUBLIC_COMMON_BINDINGS_POLICY_H_
 
 namespace content {
 
 // This enum specifies flag values for the types of JavaScript bindings exposed
@@ skipping 14 matching lines @@
   // Bindings that allows the JS content to access Mojo system API and
   // ServiceRegistry modules. The system API modules are defined in
   // //mojo/public/js and provide the ability to create Mojo primitives such as
   // message and data pipes. The ServiceRegistry module (see
   // //content/renderer/mojo/service_registry_js_wrapper.h) in turn allows these
   // Mojo primitives to be used to connect to named services exposed either by
   // the browser or testing code. These bindings should not be exposed to
   // normal web contents and are intended only for use with WebUI and layout
   // tests.
   BINDINGS_POLICY_MOJO = 1 << 3,
-  // Similar to BINDINGS_POLICY_MOJO except it's intended for use by
-  // HeadlessWebContents.
-  BINDINGS_POLICY_HEADLESS = 1 << 4,
+  // Bindings that allows main world JS content within a HeadlessWebContents to
+  // access the headless::TabSocket API.
+  BINDINGS_POLICY_HEADLESS_MAIN_WORLD = 1 << 4,
+  // Similar to BINDINGS_POLICY_HEADLESS_MAIN_WORLD except it's intended allow
+  // access only from within DevTools created isolated worlds.
+  BINDINGS_POLICY_HEADLESS_ISOLATED_WORLD = 1 << 5,
 };
-
 }
 
 #endif  // CONTENT_PUBLIC_COMMON_BINDINGS_POLICY_H_