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diff --git a/chromium/third_party/blink/renderer/platform/wtf/text/string_hash.h b/chromium/third_party/blink/renderer/platform/wtf/text/string_hash.h
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+++ b/chromium/third_party/blink/renderer/platform/wtf/text/string_hash.h
@@ -0,0 +1,180 @@
+/*
+ * Copyright (C) 2006, 2007, 2008, 2012, 2013 Apple Inc. All rights reserved
+ * Copyright (C) Research In Motion Limited 2009. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_TEXT_STRING_HASH_H_
+#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_TEXT_STRING_HASH_H_
+
+#include "third_party/blink/renderer/platform/wtf/allocator.h"
+#include "third_party/blink/renderer/platform/wtf/hash_traits.h"
+#include "third_party/blink/renderer/platform/wtf/string_hasher.h"
+#include "third_party/blink/renderer/platform/wtf/text/atomic_string.h"
+
+namespace WTF {
+
+inline bool HashTraits<String>::IsEmptyValue(const String& value) {
+  return value.IsNull();
+}
+
+inline bool HashTraits<String>::IsDeletedValue(const String& value) {
+  return HashTraits<scoped_refptr<StringImpl>>::IsDeletedValue(value.impl_);
+}
+
+inline void HashTraits<String>::ConstructDeletedValue(String& slot,
+                                                      bool zero_value) {
+  HashTraits<scoped_refptr<StringImpl>>::ConstructDeletedValue(slot.impl_,
+                                                               zero_value);
+}
+
+// The hash() functions on StringHash and CaseFoldingHash do not support null
+// strings. get(), contains(), and add() on HashMap<String,..., StringHash>
+// cause a null-pointer dereference when passed null strings.
+
+// FIXME: We should really figure out a way to put the computeHash function
+// that's currently a member function of StringImpl into this file so we can be
+// a little closer to having all the nearly-identical hash functions in one
+// place.
+
+struct StringHash {
+  STATIC_ONLY(StringHash);
+  static unsigned GetHash(StringImpl* key) { return key->GetHash(); }
+  static inline bool Equal(const StringImpl* a, const StringImpl* b) {
+    return EqualNonNull(a, b);
+  }
+
+  static unsigned GetHash(const scoped_refptr<StringImpl>& key) {
+    return key->GetHash();
+  }
+  static bool Equal(const scoped_refptr<StringImpl>& a,
+                    const scoped_refptr<StringImpl>& b) {
+    return Equal(a.get(), b.get());
+  }
+
+  static unsigned GetHash(const String& key) { return key.Impl()->GetHash(); }
+  static bool Equal(const String& a, const String& b) {
+    return Equal(a.Impl(), b.Impl());
+  }
+
+  static const bool safe_to_compare_to_empty_or_deleted = false;
+};
+
+class CaseFoldingHash {
+  STATIC_ONLY(CaseFoldingHash);
+
+ public:
+  static unsigned GetHash(const UChar* data, unsigned length) {
+    return StringHasher::ComputeHashAndMaskTop8Bits<UChar, FoldCase<UChar>>(
+        data, length);
+  }
+
+  static unsigned GetHash(StringImpl* str) {
+    if (str->Is8Bit())
+      return GetHash(str->Characters8(), str->length());
+    return GetHash(str->Characters16(), str->length());
+  }
+
+  static unsigned GetHash(const LChar* data, unsigned length) {
+    return StringHasher::ComputeHashAndMaskTop8Bits<LChar, FoldCase<LChar>>(
+        data, length);
+  }
+
+  static inline unsigned GetHash(const char* data, unsigned length) {
+    return CaseFoldingHash::GetHash(reinterpret_cast<const LChar*>(data),
+                                    length);
+  }
+
+  static inline unsigned GetHash(const char* data) {
+    return CaseFoldingHash::GetHash(reinterpret_cast<const LChar*>(data),
+                                    strlen(data));
+  }
+
+  static inline bool Equal(const StringImpl* a, const StringImpl* b) {
+    DCHECK(a);
+    DCHECK(b);
+    // Save one branch inside each StringView by derefing the StringImpl,
+    // and another branch inside the compare function by skipping the null
+    // checks.
+    return DeprecatedEqualIgnoringCaseAndNullity(*a, *b);
+  }
+
+  static unsigned GetHash(const scoped_refptr<StringImpl>& key) {
+    return GetHash(key.get());
+  }
+
+  static bool Equal(const scoped_refptr<StringImpl>& a,
+                    const scoped_refptr<StringImpl>& b) {
+    return Equal(a.get(), b.get());
+  }
+
+  static unsigned GetHash(const String& key) { return GetHash(key.Impl()); }
+  static unsigned GetHash(const AtomicString& key) {
+    return GetHash(key.Impl());
+  }
+  static bool Equal(const String& a, const String& b) {
+    return Equal(a.Impl(), b.Impl());
+  }
+  static bool Equal(const AtomicString& a, const AtomicString& b) {
+    return (a == b) || Equal(a.Impl(), b.Impl());
+  }
+
+  static const bool safe_to_compare_to_empty_or_deleted = false;
+
+ private:
+  // Private so no one uses this in the belief that it will return the
+  // correctly-folded code point in all cases (see comment below).
+  template <typename T>
+  static inline UChar FoldCase(T ch) {
+    if (std::is_same<T, LChar>::value)
+      return StringImpl::kLatin1CaseFoldTable[ch];
+    // It's possible for WTF::Unicode::foldCase() to return a 32-bit value
+    // that's not representable as a UChar.  However, since this is rare and
+    // deterministic, and the result of this is merely used for hashing, go
+    // ahead and clamp the value.
+    return static_cast<UChar>(WTF::Unicode::FoldCase(ch));
+  }
+};
+
+// This hash can be used in cases where the key is a hash of a string, but we
+// don't want to store the string. It's not really specific to string hashing,
+// but all our current uses of it are for strings.
+struct AlreadyHashed : IntHash<unsigned> {
+  STATIC_ONLY(AlreadyHashed);
+  static unsigned GetHash(unsigned key) { return key; }
+
+  // To use a hash value as a key for a hash table, we need to eliminate the
+  // "deleted" value, which is negative one. That could be done by changing
+  // the string hash function to never generate negative one, but this works
+  // and is still relatively efficient.
+  static unsigned AvoidDeletedValue(unsigned hash) {
+    DCHECK(hash);
+    unsigned new_hash = hash | (!(hash + 1) << 31);
+    DCHECK(new_hash);
+    DCHECK_NE(new_hash, 0xFFFFFFFF);
+    return new_hash;
+  }
+};
+
+}  // namespace WTF
+
+using WTF::AlreadyHashed;
+using WTF::CaseFoldingHash;
+using WTF::StringHash;
+
+#endif