Fixed perf regression by removing tree traversal for text sibling.

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 243 matching lines @@
     "StringCallback.cpp",
     "StringCallback.h",
     "StyleChangeReason.cpp",
     "StyleChangeReason.h",
     "StyleElement.cpp",
     "StyleElement.h",
     "StyleEngine.cpp",
     "StyleEngine.h",
     "StyleEngineContext.cpp",
     "StyleEngineContext.h",
+    "StyleReattachData.h",
     "StyleSheetCandidate.cpp",
     "StyleSheetCandidate.h",
     "StyleSheetCollection.cpp",
     "StyleSheetCollection.h",
     "SynchronousMutationNotifier.cpp",
     "SynchronousMutationNotifier.h",
     "SynchronousMutationObserver.cpp",
     "SynchronousMutationObserver.h",
     "TagCollection.cpp",
     "TagCollection.h",
@@ skipping 117 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",
   ]
 }