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

third_party/WebKit/public/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/buildflag_header.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 import("//third_party/WebKit/public/public_features.gni")
 import("//third_party/WebKit/Source/config.gni")
 import("//third_party/WebKit/Source/core/core.gni")
 import("//tools/grit/grit_rule.gni")
@@ skipping 206 matching lines @@
     "platform/WebIconSizesParser.h",
     "platform/WebImage.h",
     "platform/WebImageCaptureFrameGrabber.h",
     "platform/WebImageGenerator.h",
     "platform/WebImageLayer.h",
     "platform/WebInbandTextTrack.h",
     "platform/WebInbandTextTrackClient.h",
     "platform/WebInputEvent.h",
     "platform/WebInputEventResult.h",
     "platform/WebInsecureRequestPolicy.h",
+    "platform/WebIsolatedWorldIds.h",
     "platform/WebKeyboardEvent.h",
     "platform/WebLayer.h",
     "platform/WebLayerPositionConstraint.h",
     "platform/WebLayerScrollClient.h",
     "platform/WebLayerStickyPositionConstraint.h",
     "platform/WebLayerTreeView.h",
     "platform/WebLayoutAndPaintAsyncCallback.h",
     "platform/WebLoadingBehaviorFlag.h",
     "platform/WebLocalizedString.h",
     "platform/WebMediaConstraints.h",
@@ skipping 590 matching lines @@
   sources = [
     "web/ConsoleMessageStructTraits.cpp",
     "web/ConsoleMessageStructTraits.h",
   ]
   deps = [
     ":blink_headers",
     ":mojo_bindings_shared__generator",
     "//mojo/public/cpp/bindings:struct_traits",
   ]
 }