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

content/public/common/bindings_policy.h

Index: content/public/common/bindings_policy.h
diff --git a/content/public/common/bindings_policy.h b/content/public/common/bindings_policy.h
index 8ae87d2f7872faec68fede599d04f4293de533df..993c8201173ab15d5de25aa3137485b3f283ba03 100644
--- a/content/public/common/bindings_policy.h
+++ b/content/public/common/bindings_policy.h
@@ -32,13 +32,11 @@
   // normal web contents and are intended only for use with WebUI and layout
   // tests.
   BINDINGS_POLICY_MOJO = 1 << 3,
-  // 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,
+  // Similar to BINDINGS_POLICY_MOJO except it's intended for use by
+  // HeadlessWebContents.
+  BINDINGS_POLICY_HEADLESS = 1 << 4,
 };
+
 }
 
 #endif  // CONTENT_PUBLIC_COMMON_BINDINGS_POLICY_H_