Remove MainThreadTaskRunner

third_party/WebKit/Source/core/dom/BUILD.gn

 # Copyright 2016 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("//third_party/WebKit/Source/core/core.gni")
 
 blink_core_sources("dom") {
   split_count = 5
 
   sources = [
@@ skipping 156 matching lines @@
     "IntersectionObserverEntry.h",
     "Iterator.h",
     "LayoutTreeBuilder.cpp",
     "LayoutTreeBuilder.h",
     "LayoutTreeBuilderTraversal.cpp",
     "LayoutTreeBuilderTraversal.h",
     "LiveNodeList.cpp",
     "LiveNodeList.h",
     "LiveNodeListBase.cpp",
     "LiveNodeListBase.h",
-    "MainThreadTaskRunner.cpp",
-    "MainThreadTaskRunner.h",
     "MessageChannel.cpp",
     "MessageChannel.h",
     "MessagePort.cpp",
     "MutationCallback.h",
     "MutationObserver.cpp",
     "MutationObserver.h",
     "MutationObserverInterestGroup.cpp",
     "MutationObserverInterestGroup.h",
     "MutationObserverRegistration.cpp",
     "MutationObserverRegistration.h",
@@ skipping 205 matching lines @@
     "shadow/SlotAssignment.h",
     "shadow/SlotScopedTraversal.cpp",
     "shadow/SlotScopedTraversal.h",
   ]
 
   configs += [
     # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
     "//build/config/compiler:no_size_t_to_int_warning",
   ]
 }