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

headless/public/headless_web_contents.h

Index: headless/public/headless_web_contents.h
diff --git a/headless/public/headless_web_contents.h b/headless/public/headless_web_contents.h
index 899249c11a0e03f41f5207126e06bb1b404aef5b..9c1de12ecb254ff2cd1712e6a5c1c96580c55adb 100644
--- a/headless/public/headless_web_contents.h
+++ b/headless/public/headless_web_contents.h
@@ -112,15 +112,9 @@
   // Specify the initial window size (default is configured in browser options).
   Builder& SetWindowSize(const gfx::Size& size);
 
-  enum class TabSocketType {
-    NONE,           // No TabSocket binds created (default).
-    MAIN_WORLD,     // TabSocket bindings available only to the main world.
-    ISOLATED_WORLD  // TabSocket bindings available only to isolated worlds
-                    // created via DevTools protocol.
-  };
-
-  // Sets the type of TabSocket to be created, if any.
-  Builder& SetTabSocketType(TabSocketType type);
+  // Whether or not a headless tab socket should be created, to allow JS -> C++
+  // embedder communications.
+  Builder& CreateTabSocket(bool create_tab_socket);
 
   // The returned object is owned by HeadlessBrowser. Call
   // HeadlessWebContents::Close() to dispose it.
@@ -160,7 +154,7 @@
   GURL initial_url_ = GURL("about:blank");
   gfx::Size window_size_;
   std::list<MojoService> mojo_services_;
-  TabSocketType tab_socket_type_ = TabSocketType::NONE;
+  bool create_tab_socket_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(Builder);
 };