[DMC #24] Add SpellingMarker and GrammarMarker (subclasses of DocumentMarker)

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

Index: third_party/WebKit/Source/core/editing/markers/SpellCheckMarker.h
diff --git a/third_party/WebKit/Source/core/editing/markers/SpellCheckMarker.h b/third_party/WebKit/Source/core/editing/markers/SpellCheckMarker.h
new file mode 100644
index 0000000000000000000000000000000000000000..053f7c55248d98241cb09e957769e0e0923f0307
--- /dev/null
+++ b/third_party/WebKit/Source/core/editing/markers/SpellCheckMarker.h
@@ -0,0 +1,41 @@
+// 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 SpellCheckMarker_h
+#define SpellCheckMarker_h
+
+#include "core/editing/markers/DocumentMarker.h"
+
+namespace blink {
+
+// A subclass of DocumentMarker used to implement functionality shared between
+// spelling and grammar markers. These two marker types both store a
+// description string that can contain suggested replacements for a misspelling
+// or grammar error.
+class CORE_EXPORT SpellCheckMarker : public DocumentMarker {
+ public:
+  SpellCheckMarker(DocumentMarker::MarkerType,
+                   unsigned start_offset,
+                   unsigned end_offset,
+                   const String& description);
+
+  const String& Description() const { return description_; }
+
+ private:
+  const String description_;
+
+  DISALLOW_COPY_AND_ASSIGN(SpellCheckMarker);
+};
+
+bool CORE_EXPORT IsSpellCheckMarker(const DocumentMarker&);
+
+DEFINE_TYPE_CASTS(SpellCheckMarker,
+                  DocumentMarker,
+                  marker,
+                  IsSpellCheckMarker(*marker),
+                  IsSpellCheckMarker(marker));
+
+}  // namespace blink
+
+#endif