Empty list items after drag&drop in contentEditable divs
https://bugs.webkit.org/show_bug.cgi?id=110610

Reviewed by Ryosuke Niwa.

Source/WebCore:

Perform a cleanup after moving operations. This will mainly prune
extra placeholders left by the editing algorithms. Also do not
leave empty <li> when moving them around inside a list element.

Tests: editing/pasteboard/cleanup-on-move.html
       editing/pasteboard/drag-list-item.html

* editing/MoveSelectionCommand.cpp:
(WebCore::MoveSelectionCommand::doApply): perform
cleanupAfterDeletion().
* editing/ReplaceSelectionCommand.cpp:
(WebCore::ReplaceSelectionCommand::insertAsListItems): do not
insert an empty list item.
* editing/MoveSelectionCommand.cpp:
(WebCore::MoveSelectionCommand::doApply):
* editing/ReplaceSelectionCommand.cpp:
(WebCore::ReplaceSelectionCommand::insertAsListItems):

LayoutTests:

Some placeholders should not be left after performing a cleanup in
move operations, this includes the empty list items generated when
moving around list items inside a list.

I'm also moving drag-list-item.html to editing/pasteboard because
it fits much better there than under editing/selection.

* editing/pasteboard/cleanup-on-move-expected.txt: Added.
* editing/pasteboard/cleanup-on-move.html: Added.
* editing/pasteboard/drag-list-item-expected.txt: Renamed from LayoutTests/editing/selection/drag-list-item-expected.txt.
* editing/pasteboard/drag-list-item.html: Renamed from LayoutTests/editing/selection/drag-list-item.html.
* editing/pasteboard/resources/select-and-drag.js: Added.
(selectAndDragToTarget): Selects nodes and drops them after a target node.
* editing/pasteboard/drag-drop-list-expected.txt: Removed an empty <li>.
* editing/pasteboard/paste-list-004-expected.txt: Removed 2 empty <li>.
* editing/pasteboard/paste-list-004.html: Ditto.
* editing/selection/4895428-1-expected.txt: Removed a <br>.
* editing/selection/4895428-4-expected.txt: Ditto.
* fast/events/ondragenter-expected.txt: Removed a blank line.
* platform/chromium/fast/events/ondragenter-expected.txt: Ditto.
* platform/efl/TestExpectations: Added cleanup-on-move.html to the skipped list.
* platform/mac-wk2/TestExpectations: Ditto.
* platform/qt/TestExpectations: Ditto.
* platform/win/fast/events/ondragenter-expected.txt: Removed a blank line.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@145798 268f45cc-cd09-0410-ab3c-d52691b4dbfc