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diff --git a/chromium/third_party/blink/renderer/platform/fonts/font_fallback_iterator.h b/chromium/third_party/blink/renderer/platform/fonts/font_fallback_iterator.h
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+++ b/chromium/third_party/blink/renderer/platform/fonts/font_fallback_iterator.h
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+// Copyright 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.
+
+#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_FONT_FALLBACK_ITERATOR_H_
+#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_FONTS_FONT_FALLBACK_ITERATOR_H_
+
+#include "base/memory/scoped_refptr.h"
+#include "third_party/blink/renderer/platform/fonts/font_data_for_range_set.h"
+#include "third_party/blink/renderer/platform/fonts/font_fallback_priority.h"
+#include "third_party/blink/renderer/platform/wtf/hash_map.h"
+#include "third_party/blink/renderer/platform/wtf/ref_counted.h"
+#include "third_party/blink/renderer/platform/wtf/text/unicode.h"
+#include "third_party/blink/renderer/platform/wtf/vector.h"
+
+namespace blink {
+
+class FontDescription;
+class FontFallbackList;
+class SimpleFontData;
+
+class FontFallbackIterator : public RefCounted<FontFallbackIterator> {
+  WTF_MAKE_NONCOPYABLE(FontFallbackIterator);
+
+ public:
+  static scoped_refptr<FontFallbackIterator> Create(const FontDescription&,
+                                             scoped_refptr<FontFallbackList>,
+                                             FontFallbackPriority);
+
+  bool HasNext() const { return fallback_stage_ != kOutOfLuck; };
+
+  // Some system fallback APIs (Windows, Android) require a character, or a
+  // portion of the string to be passed.  On Mac and Linux, we get a list of
+  // fonts without passing in characters.
+  scoped_refptr<FontDataForRangeSet> Next(const Vector<UChar32>& hint_list);
+
+ private:
+  FontFallbackIterator(const FontDescription&,
+                       scoped_refptr<FontFallbackList>,
+                       FontFallbackPriority);
+  bool RangeSetContributesForHint(const Vector<UChar32> hint_list,
+                                  const FontDataForRangeSet*);
+  bool AlreadyLoadingRangeForHintChar(UChar32 hint_char);
+  void WillUseRange(const AtomicString& family, const FontDataForRangeSet&);
+
+  scoped_refptr<FontDataForRangeSet> UniqueOrNext(
+      scoped_refptr<FontDataForRangeSet> candidate,
+      const Vector<UChar32>& hint_list);
+
+  scoped_refptr<SimpleFontData> FallbackPriorityFont(UChar32 hint);
+  scoped_refptr<SimpleFontData> UniqueSystemFontForHintList(
+      const Vector<UChar32>& hint_list);
+
+  const FontDescription& font_description_;
+  scoped_refptr<FontFallbackList> font_fallback_list_;
+  int current_font_data_index_;
+  unsigned segmented_face_index_;
+
+  enum FallbackStage {
+    kFallbackPriorityFonts,
+    kFontGroupFonts,
+    kSegmentedFace,
+    kPreferencesFonts,
+    kSystemFonts,
+    kOutOfLuck
+  };
+
+  FallbackStage fallback_stage_;
+  HashSet<UChar32> previously_asked_for_hint_;
+  // FontFallbackIterator is meant for single use by HarfBuzzShaper,
+  // traversing through the fonts for shaping only once. We must not return
+  // duplicate FontDataForRangeSet objects from the next() iteration functions
+  // as returning a duplicate value causes a shaping run that won't return any
+  // results.
+  HashSet<uint32_t> unique_font_data_for_range_sets_returned_;
+  Vector<scoped_refptr<FontDataForRangeSet>> tracked_loading_range_sets_;
+  FontFallbackPriority font_fallback_priority_;
+};
+
+}  // namespace blink
+
+#endif