[ActiveSuggestionMarker #2] Add ActiveSuggestionMarker

third_party/WebKit/Source/core/editing/markers/ActiveSuggestionMarkerListImpl.h

Index: third_party/WebKit/Source/core/editing/markers/ActiveSuggestionMarkerListImpl.h
diff --git a/third_party/WebKit/Source/core/editing/markers/ActiveSuggestionMarkerListImpl.h b/third_party/WebKit/Source/core/editing/markers/ActiveSuggestionMarkerListImpl.h
new file mode 100644
index 0000000000000000000000000000000000000000..c00182318b613e3019c3e933d5977321990a9f7d
--- /dev/null
+++ b/third_party/WebKit/Source/core/editing/markers/ActiveSuggestionMarkerListImpl.h
@@ -0,0 +1,49 @@
+// Copyright 2017 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 ActiveSuggestionMarkerListImpl_h
+#define ActiveSuggestionMarkerListImpl_h
+
+#include "core/editing/markers/DocumentMarkerList.h"
+
+namespace blink {
+
+// Implementation of DocumentMarkerList for ActiveSuggestion markers.
+// ActiveSuggestion markers are always inserted in order, aside from some
+// potential oddball cases (e.g. splitting the marker list into two nodes, then
+// undoing the split). This means we can keep the list in sorted order to do
+// some operations more efficiently, while still being able to do inserts in
+// O(1) time at the end of the list.
+class CORE_EXPORT ActiveSuggestionMarkerListImpl final
+    : public DocumentMarkerList {
+ public:
+  ActiveSuggestionMarkerListImpl() = default;
+
+  // DocumentMarkerList implementations
+  DocumentMarker::MarkerType MarkerType() const final;
+
+  bool IsEmpty() const final;
+
+  void Add(DocumentMarker*) final;
+  void Clear() final;
+
+  const HeapVector<Member<DocumentMarker>>& GetMarkers() const final;
+
+  bool MoveMarkers(int length, DocumentMarkerList* dst_list) final;
+  bool RemoveMarkers(unsigned start_offset, int length) final;
+  bool ShiftMarkers(unsigned offset,
+                    unsigned old_length,
+                    unsigned new_length) final;
+
+  DECLARE_VIRTUAL_TRACE();
+
+ private:
+  HeapVector<Member<DocumentMarker>> markers_;
+
+  DISALLOW_COPY_AND_ASSIGN(ActiveSuggestionMarkerListImpl);
+};
+
+}  // namespace blink
+
+#endif  // ActiveSuggestionMarkerListImpl_h