[ActiveSuggestionMarker #1] Introduce abstract StyleableMarker subclass of DocumentMarker

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

+// 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/StyleableMarker.h"
+
+namespace blink {
+
+StyleableMarker::StyleableMarker(unsigned start_offset,
+                                 unsigned end_offset,
+                                 Color underline_color,
+                                 Thickness thickness,
+                                 Color background_color)
+    : DocumentMarker(start_offset, end_offset),
+      underline_color_(underline_color),
+      background_color_(background_color),
+      thickness_(thickness) {}
+
+Color StyleableMarker::UnderlineColor() const {
+  return underline_color_;
+}
+
+bool StyleableMarker::IsThick() const {
+  return thickness_ == Thickness::kThick;
+}
+
+Color StyleableMarker::BackgroundColor() const {
+  return background_color_;
+}
+
+bool IsStyleableMarker(const DocumentMarker& marker) {
+  DocumentMarker::MarkerType type = marker.GetType();
+  return type == DocumentMarker::kComposition;
+}
+
+}  // namespace blink