Add SequencedTaskRunnerHandle to get a SequencedTaskRunner for the current thread / sequence.

base/BUILD.gn

 # Copyright (c) 2013 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/config/compiler/compiler.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 
 if (is_android) {
   import("//build/config/android/rules.gni")
@@ skipping 506 matching lines @@
     "threading/platform_thread.h",
     "threading/platform_thread_android.cc",
     "threading/platform_thread_internal_posix.cc",
     "threading/platform_thread_internal_posix.h",
     "threading/platform_thread_linux.cc",
     "threading/platform_thread_mac.mm",
     "threading/platform_thread_posix.cc",
     "threading/platform_thread_win.cc",
     "threading/post_task_and_reply_impl.cc",
     "threading/post_task_and_reply_impl.h",
+    "threading/sequenced_task_runner_handle.cc",
+    "threading/sequenced_task_runner_handle.h",
     "threading/sequenced_worker_pool.cc",
     "threading/sequenced_worker_pool.h",
     "threading/simple_thread.cc",
     "threading/simple_thread.h",
     "threading/thread.cc",
     "threading/thread.h",
     "threading/thread_checker.h",
     "threading/thread_checker_impl.cc",
     "threading/thread_checker_impl.h",
     "threading/thread_collision_warner.cc",
@@ skipping 1149 matching lines @@
 
   # GYP: //base.gyp:base_java_unittest_support
   android_library("base_java_unittest_support") {
     deps = [
       ":base_java",
     ]
     java_files =
         [ "test/android/java/src/org/chromium/base/ContentUriTestUtils.java" ]
   }
 }