[MarkersIntersectingRange #2.05] Add DocumentMarkerList::FirstMarkerIntersectingRange()

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

Index: third_party/WebKit/Source/core/editing/markers/DocumentMarkerListEditor.cpp
diff --git a/third_party/WebKit/Source/core/editing/markers/DocumentMarkerListEditor.cpp b/third_party/WebKit/Source/core/editing/markers/DocumentMarkerListEditor.cpp
index 15e67cb4b31a065da253ce897e6a2f032f53c138..a65f41ca4bef356f5f583e42fe10074bb3e52402 100644
--- a/third_party/WebKit/Source/core/editing/markers/DocumentMarkerListEditor.cpp
+++ b/third_party/WebKit/Source/core/editing/markers/DocumentMarkerListEditor.cpp
@@ -166,6 +166,26 @@ bool DocumentMarkerListEditor::ShiftMarkersContentIndependent(
   return did_shift_marker;
 }
 
+DocumentMarker* DocumentMarkerListEditor::FirstMarkerIntersectingRange(
+    const MarkerList& list,
+    unsigned start_offset,
+    unsigned end_offset) {
+  DCHECK_LE(start_offset, end_offset);
+
+  const auto& marker_it =
+      std::lower_bound(list.begin(), list.end(), start_offset,
+                       [](const DocumentMarker* marker, unsigned start_offset) {
+                         return marker->EndOffset() <= start_offset;
+                       });
+  if (marker_it == list.end())
+    return nullptr;
+
+  DocumentMarker* marker = *marker_it;
+  if (marker->StartOffset() >= end_offset)
+    return nullptr;
+  return marker;
+}
+
 HeapVector<Member<DocumentMarker>>
 DocumentMarkerListEditor::MarkersIntersectingRange(const MarkerList& list,
                                                    unsigned start_offset,