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

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

Index: third_party/WebKit/Source/core/editing/markers/SpellCheckMarker.cpp
diff --git a/third_party/WebKit/Source/core/editing/markers/SpellCheckMarker.cpp b/third_party/WebKit/Source/core/editing/markers/SpellCheckMarker.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..f59750ac20e55c0888c81e3fcfda99cf60774043
--- /dev/null
+++ b/third_party/WebKit/Source/core/editing/markers/SpellCheckMarker.cpp
@@ -0,0 +1,22 @@
+// 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.
+
+#include "core/editing/markers/SpellCheckMarker.h"
+
+namespace blink {
+
+SpellCheckMarker::SpellCheckMarker(DocumentMarker::MarkerType type,
+                                   unsigned start_offset,
+                                   unsigned end_offset,
+                                   const String& description)
+    : DocumentMarker(type, start_offset, end_offset),
+      description_(description) {
+  DCHECK_LT(start_offset, end_offset);
+}
+
+const String& SpellCheckMarker::Description() const {
+  return description_;
+}
+
+}  // namespace blink