Introduce previousPositionOf() for VisiblePosition

Source/core/editing/commands/ApplyBlockElementCommand.cpp

Index: Source/core/editing/commands/ApplyBlockElementCommand.cpp
diff --git a/Source/core/editing/commands/ApplyBlockElementCommand.cpp b/Source/core/editing/commands/ApplyBlockElementCommand.cpp
index 4ecb424767bd1789f12e366d82967d0fa8036764..20961e6a8b03d3322125008ce92b5448eb7f9dfe 100644
--- a/Source/core/editing/commands/ApplyBlockElementCommand.cpp
+++ b/Source/core/editing/commands/ApplyBlockElementCommand.cpp
@@ -72,10 +72,10 @@ void ApplyBlockElementCommand::doApply()
     // ends "inside" that paragraph, so it would be confusing if Indent/Outdent
     // operated on that paragraph.
     // FIXME: We paint the gap before some paragraphs that are indented with left
-    // margin/padding, but not others.  We should make the gap painting more consistent and
-    // then use a left margin/padding rule here.
+    // margin/padding, but not others.  We should make the gap painting more
+    // consistent and then use a left margin/padding rule here.
     if (visibleEnd.deepEquivalent() != visibleStart.deepEquivalent() && isStartOfParagraph(visibleEnd)) {
-        VisibleSelection newSelection(visibleStart, visibleEnd.previous(CannotCrossEditingBoundary), endingSelection().isDirectional());
+        VisibleSelection newSelection(visibleStart, previousPositionOf(visibleEnd, CannotCrossEditingBoundary), endingSelection().isDirectional());
         if (newSelection.isNone())
             return;
         setEndingSelection(newSelection);