Remove mojo::WTFArray.

mojo/public/cpp/bindings/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.
 
 interfaces_bindings_gen_dir = "$root_gen_dir/mojo/public/interfaces/bindings"
 
 component("bindings") {
   sources = [
     # Normally, targets should depend on the source_sets generated by mojom
     # targets. However, the generated source_sets use portions of the bindings
@@ skipping 152 matching lines @@
   sources = [
     "enum_traits.h",
     "struct_traits.h",
   ]
 }
 
 if (!is_ios) {
   # TODO(yzshen): crbug.com/617718 Consider moving this into blink.
   source_set("wtf_support") {
     sources = [
-      "array_traits_wtf.h",
       "array_traits_wtf_vector.h",
       "lib/string_traits_wtf.cc",
       "lib/wtf_clone_equals_util.h",
       "lib/wtf_hash_util.h",
       "lib/wtf_serialization.h",
       "map_traits_wtf_hash_map.h",
       "string_traits_wtf.h",
-      "wtf_array.h",
     ]
 
     public_deps = [
       ":bindings",
       "//third_party/WebKit/Source/wtf",
     ]
 
     public_configs = [ "//third_party/WebKit/Source:config" ]
   }
 }