Let Selection.deleteFromDocument not delete a character when the selection is a caret.

Source/core/page/DOMSelection.cpp

 /*
  * Copyright (C) 2007, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2012 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.
@@ skipping 429 matching lines @@
 void DOMSelection::deleteFromDocument()
 {
     if (!m_frame)
         return;
 
     FrameSelection& selection = m_frame->selection();
 
     if (selection.isNone())
         return;
 
-    if (isCollapsed())
-        selection.modify(FrameSelection::AlterationExtend, DirectionBackward, CharacterGranularity);
-
     RefPtrWillBeRawPtr<Range> selectedRange = selection.selection().toNormalizedRange();
     if (!selectedRange)
         return;
 
     selectedRange->deleteContents(ASSERT_NO_EXCEPTION);
 
     setBaseAndExtent(selectedRange->startContainer(ASSERT_NO_EXCEPTION), selectedRange->startOffset(), selectedRange->startContainer(), selectedRange->startOffset(), ASSERT_NO_EXCEPTION);
 }
 
 bool DOMSelection::containsNode(const Node* n, bool allowPartial) const
@@ skipping 90 matching lines @@
     return node->document() == m_frame->document();
 }
 
 void DOMSelection::addConsoleError(const String& message)
 {
     if (m_treeScope)
         m_treeScope->document().addConsoleMessage(JSMessageSource, ErrorMessageLevel, message);
 }
 
 } // namespace WebCore