Add Get/SetUniqueIdForProcess.

base/process/BUILD.gn

 # Copyright (c) 2015 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.
 
 source_set("process") {
   sources = [
     "internal_linux.cc",
     "internal_linux.h",
     "kill.cc",
     "kill.h",
     "kill_mac.cc",
     "kill_posix.cc",
     "kill_win.cc",
     "launch.cc",
     "launch.h",
     "launch_ios.cc",
     "launch_mac.cc",
     "launch_posix.cc",
     "launch_win.cc",
     "memory.cc",
     "memory.h",
     "memory_linux.cc",
     "memory_mac.mm",
     "memory_win.cc",
     "process.h",
+    "process_handle.cc",
     "process_handle_freebsd.cc",
     "process_handle_linux.cc",
     "process_handle_mac.cc",
     "process_handle_openbsd.cc",
     "process_handle_posix.cc",
     "process_handle_win.cc",
     "process_info.h",
     "process_info_linux.cc",
     "process_info_mac.cc",
     "process_info_win.cc",
@@ skipping 67 matching lines @@
 
   deps = [
     "//base/memory",
     "//base/third_party/dynamic_annotations",
   ]
 
   allow_circular_includes_from = [ "//base/memory" ]
 
   visibility = [ "//base/*" ]
 }