Add DocumentMarkerList interface

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

Index: third_party/WebKit/Source/core/editing/markers/DocumentMarkerList.h
diff --git a/third_party/WebKit/Source/core/editing/markers/DocumentMarkerList.h b/third_party/WebKit/Source/core/editing/markers/DocumentMarkerList.h
new file mode 100644
index 0000000000000000000000000000000000000000..384b60b86ca4c4709389d181aa26d55fa091d42f
--- /dev/null
+++ b/third_party/WebKit/Source/core/editing/markers/DocumentMarkerList.h
@@ -0,0 +1,55 @@
+// 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 DocumentMarkerList_h
+#define DocumentMarkerList_h
+
+#include "core/editing/markers/DocumentMarker.h"
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class DocumentMarkerList
+    : public GarbageCollectedFinalized<DocumentMarkerList> {
+ public:
+  DocumentMarkerList();
+
+  virtual ~DocumentMarkerList();
+
+  virtual bool Empty() const = 0;
+
+  virtual void Add(DocumentMarker*) = 0;
+  virtual void Clear() = 0;
+
+  virtual void AppendMarkersToInputList(DocumentMarkerVector* list) const = 0;
+
+  // Moves markers from src_node to dst_node. Markers are moved if their start
+  // offset is less than length. Markers that run past that point are truncated.
+
+  // Returns true if at least one marker is moved, false otherwise
+  virtual bool MoveMarkers(int length, DocumentMarkerList* dst_list) = 0;
+
+  // Removes markers that have non-zero intersection with the range
+  // [start_offset, start_offset + length] (i.e., it's not enough that an
+  // endpoint touches this range, there must be overlap).
+
+  // Returns true if at least one marker is removed, false otherwise
+  virtual bool RemoveMarkers(unsigned start_offset, int length) = 0;
+
+  // Updates markers in response to a text edit occurring at the specified
+  // offset that changes a range of text (possibly empty) of length old_length
+  // into a new new range of text (also possibly empty) of length new_length.
+
+  // Returns true if at least one marker is shifted or removed, false otherwise
+  virtual bool ShiftMarkers(unsigned offset,
+                            unsigned old_length,
+                            unsigned new_length) = 0;
+
+  DEFINE_INLINE_VIRTUAL_TRACE() {}
+  DISALLOW_COPY_AND_ASSIGN(DocumentMarkerList);
+};
+
+}  // namespace blink
+
+#endif  // DocumentMarkerList_h