WebKit merge 40668:40722 part 1.

third_party/WebKit/WebCore/dom/Position.h

Index: third_party/WebKit/WebCore/dom/Position.h
===================================================================
--- third_party/WebKit/WebCore/dom/Position.h	(revision 9310)
+++ third_party/WebKit/WebCore/dom/Position.h	(working copy)
@@ -40,7 +40,11 @@
 class Range;
 class RenderObject;
 
-enum EUsingComposedCharacters { NotUsingComposedCharacters = false, UsingComposedCharacters = true };
+enum PositionMoveType {
+    CodePoint,       // Move by a single code point.
+    Character,       // Move to the next Unicode character break.
+    BackwardDeletion // Subject to platform conventions.
+};
 
 // FIXME: Reduce the number of operations we have on a Position.
 // This should be more like a humble struct, without so many different
@@ -69,9 +73,10 @@
     // Move up or down the DOM by one position.
     // Offsets are computed using render text for nodes that have renderers - but note that even when
     // using composed characters, the result may be inside a single user-visible character if a ligature is formed.
-    Position previous(EUsingComposedCharacters usingComposedCharacters=NotUsingComposedCharacters) const;
-    Position next(EUsingComposedCharacters usingComposedCharacters=NotUsingComposedCharacters) const;
+    Position previous(PositionMoveType = CodePoint) const;
+    Position next(PositionMoveType = CodePoint) const;
     static int uncheckedPreviousOffset(const Node*, int current);
+    static int uncheckedPreviousOffsetForBackwardDeletion(const Node*, int current);
     static int uncheckedNextOffset(const Node*, int current);
 
     bool atStart() const;