Revert of WTF::ThreadSpecific should use base::ThreadLocalStorage.

third_party/WebKit/Source/wtf/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("//testing/test.gni")
 import("//third_party/WebKit/Source/config.gni")
 
 # The list of files is kept in the .gypi.
 gypi_values = exec_script("//build/gypi_to_gn.py",
                           [ rebase_path("wtf.gypi") ],
@@ skipping 55 matching lines @@
     "//base",
     "//third_party/icu",
   ]
 
   if (is_win) {
     sources -= [ "ThreadingPthreads.cpp" ]
 
     cflags = [ "/wd4068" ]  # Unknown pragma.
   } else {
     # Non-Windows.
-    sources -= [ "ThreadingWin.cpp" ]
+    sources -= [
+      "ThreadSpecificWin.cpp",
+      "ThreadingWin.cpp",
+    ]
   }
 
   if (is_android) {
     libs = [ "log" ]
   }
   if (is_linux) {
     libs = [ "dl" ]
   }
 
   if (is_mac) {
@@ skipping 32 matching lines @@
   configs += [ "//third_party/WebKit/Source:config" ]
 
   deps = [
     ":wtf",
     "//base",
     "//base/test:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }