Move files in wtf/ to platform/wtf/ (Part 5).

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.
 
 assert(!is_ios)
 
 import("//testing/test.gni")
 import("//third_party/WebKit/Source/config.gni")
 
 visibility = [
@@ skipping 53 matching lines @@
     "InstanceCounter.cpp",
     "InstanceCounter.h",
     "LeakAnnotations.h",
     "LinkedStack.h",
     "ListHashSet.h",
     "Locker.h",
     "MathExtras.h",
     "NonCopyingSort.h",
     "Noncopyable.h",
     "NotFound.h",
+    "NotNull.h",
     "Optional.h",
     "PassRefPtr.h",
     "PrintStream.cpp",
     "PrintStream.h",
     "PtrUtil.h",
     "RefCounted.h",
     "RefPtr.h",
     "RetainPtr.h",
     "SaturatedArithmetic.h",
     "SizeAssertions.h",
@@ skipping 244 matching lines @@
   ]
 
   deps = [
     ":wtf",
     "//base",
     "//base/test:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }