Add CompositionMarkerList in preparation for DocumentMarkerController refactor

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..87e8562396282c8684769c39e2064043c0031f1b 100644
--- a/third_party/WebKit/Source/core/editing/markers/DocumentMarker.h
+++ b/third_party/WebKit/Source/core/editing/markers/DocumentMarker.h
@@ -161,6 +161,17 @@ class CORE_EXPORT DocumentMarker : public GarbageCollected<DocumentMarker> {
   void setActiveMatch(bool);
   void clearDetails() { m_details.clear(); }
 
+  struct ShiftMarkerResult {
+    // Other classes should not call following setters.

[Xiaocheng, 2017/03/24 03:57:47]

Irrelevant change?

[rlanday, 2017/03/24 17:45:48]

oops, rebase mistake I think

+    unsigned newStartOffset;
+    unsigned newEndOffset;
+    bool shouldRemoveMarker;
+  };
+
+  ShiftMarkerResult getShiftedMarkerPosition(unsigned offset,
+                                             unsigned oldLength,
+                                             unsigned newLength) const;
+
   // Offset modifications are done by DocumentMarkerController.

[Xiaocheng, 2017/03/24 03:57:47]

DocumentMarkerList also calls them.

[rlanday, 2017/03/24 17:45:48]

Yeah, I have the comment updated in my big patch for the whole refactor, I
wasn't sure if I should change it here or not if we're not actually using the
new DocumentMarkerLists yet

[Xiaocheng, 2017/03/24 19:43:49]

Please modify the comment in this patch. Otherwise, the use of these settings in
DML looks confusing.

   // Other classes should not call following setters.
   void setStartOffset(unsigned offset) { m_startOffset = offset; }