Add SpellCheckMarkerList in preparation for DocumentMarkerController refactor

third_party/WebKit/Source/core/editing/BUILD.gn

Index: third_party/WebKit/Source/core/editing/BUILD.gn
diff --git a/third_party/WebKit/Source/core/editing/BUILD.gn b/third_party/WebKit/Source/core/editing/BUILD.gn
index 8d7757c71d1ebca587789a8154a1838bfd9b9932..6f54bb803108ea41ad87dbeb9ef08cdb62e97ae1 100644
--- a/third_party/WebKit/Source/core/editing/BUILD.gn
+++ b/third_party/WebKit/Source/core/editing/BUILD.gn
@@ -198,6 +198,8 @@ blink_core_sources("editing") {
     "markers/EditingMarkerList.h",
     "markers/RenderedDocumentMarker.cpp",
     "markers/RenderedDocumentMarker.h",
+    "markers/SpellCheckMarkerList.cpp",
+    "markers/SpellCheckMarkerList.h",
     "serializers/HTMLInterchange.cpp",
     "serializers/HTMLInterchange.h",
     "serializers/MarkupAccumulator.cpp",
@@ -294,6 +296,7 @@ source_set("unit_tests") {
     "markers/DocumentMarkerListTest.cpp",
     "markers/DocumentMarkerTest.cpp",
     "markers/EditingMarkerListTest.cpp",
+    "markers/SpellCheckMarkerListTest.cpp",
     "serializers/StyledMarkupSerializerTest.cpp",
     "spellcheck/IdleSpellCheckCallbackTest.cpp",
     "spellcheck/SpellCheckTestBase.cpp",