Introduce previousPositionOf() for VisiblePosition

Source/core/editing/commands/ApplyBlockElementCommand.cpp

 /*
  * Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 54 matching lines @@
     VisiblePosition visibleStart = endingSelection().visibleStart();
     if (visibleStart.isNull() || visibleStart.isOrphan() || visibleEnd.isNull() || visibleEnd.isOrphan())
         return;
 
     // When a selection ends at the start of a paragraph, we rarely paint
     // the selection gap before that paragraph, because there often is no gap.
     // In a case like this, it's not obvious to the user that the selection
     // 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);
     }
 
     VisibleSelection selection = selectionForParagraphIteration(endingSelection());
     VisiblePosition startOfSelection = selection.visibleStart();
     VisiblePosition endOfSelection = selection.visibleEnd();
     ASSERT(!startOfSelection.isNull());
     ASSERT(!endOfSelection.isNull());
@@ skipping 205 matching lines @@
     return element.release();
 }
 
 DEFINE_TRACE(ApplyBlockElementCommand)
 {
     visitor->trace(m_endOfLastParagraph);
     CompositeEditCommand::trace(visitor);
 }
 
 }