Rewrite references to "wtf/" to "platform/wtf/" in //mojo.

mojo/public/cpp/bindings/map_traits_wtf_hash_map.h

 // Copyright 2016 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.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_MAP_TRAITS_WTF_HASH_MAP_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_MAP_TRAITS_WTF_HASH_MAP_H_
 
 #include "base/logging.h"
 #include "mojo/public/cpp/bindings/map_traits.h"
-#include "third_party/WebKit/Source/wtf/HashMap.h"
+#include "third_party/WebKit/Source/platform/wtf/HashMap.h"
 
 namespace mojo {
 
 template <typename K, typename V>
 struct MapTraits<WTF::HashMap<K, V>> {
   using Key = K;
   using Value = V;
   using Iterator = typename WTF::HashMap<K, V>::iterator;
   using ConstIterator = typename WTF::HashMap<K, V>::const_iterator;
 
@@ skipping 34 matching lines @@
     input.insert(std::forward<IK>(key), std::forward<IV>(value));
     return true;
   }
 
   static void SetToEmpty(WTF::HashMap<K, V>* output) { output->Clear(); }
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_MAP_TRAITS_WTF_HASH_MAP_H_