Improve how DocumentMarkerController updates markers in response to text edits

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

Index: third_party/WebKit/Source/core/editing/markers/DocumentMarker.h
diff --git a/third_party/WebKit/Source/core/editing/markers/DocumentMarker.h b/third_party/WebKit/Source/core/editing/markers/DocumentMarker.h
index dbcfdf2964555be13aa50b7551bf2305f37a6fd8..7ea4dbfdee54789b8289f6ca8e4c3cc25c39cc7b 100644
--- a/third_party/WebKit/Source/core/editing/markers/DocumentMarker.h
+++ b/third_party/WebKit/Source/core/editing/markers/DocumentMarker.h
@@ -161,6 +161,16 @@ class CORE_EXPORT DocumentMarker : public GarbageCollected<DocumentMarker> {
   void setActiveMatch(bool);
   void clearDetails() { m_details.clear(); }
 
+  struct ShiftMarkerResult {
+    unsigned newStartOffset;
+    unsigned newEndOffset;
+    bool shouldRemoveMarker;
+  };
+
+  ShiftMarkerResult getShiftedMarkerPosition(unsigned offset,

[Xiaocheng, 2017/03/29 23:25:08]

Please also move its unit tests to this patch.

+                                             unsigned oldLength,
+                                             unsigned newLength) const;
+
   // Offset modifications are done by DocumentMarkerController.
   // Other classes should not call following setters.
   void setStartOffset(unsigned offset) { m_startOffset = offset; }