[Forms] Introduce SpinButtonElement.{cpp,h} into build

[Forms] Introduce SpinButtonElement.{cpp,h} into build
https://bugs.webkit.org/show_bug.cgi?id=94289

Reviewed by Kent Tamura.

This patch introduces html/shadow/SpinButtonElement.{cpp,h} into
build, files were copied from TextControlInnerElements.{cpp,h} by
bug 93943.

No new tests. This patch doesn't changes behavior.

* CMakeLists.txt: Added SpinButtonElement.cpp
* GNUmakefile.list.am: Added SpinButtonElement.{cpp,h}
* Target.pri: Added SpinButtonElement.cpp
* WebCore.gypi: Added SpinButtonElement.{cpp,h}
* WebCore.vcproj/WebCore.vcproj: Added SpinButtonElement.{cpp,h}
* WebCore.xcodeproj/project.pbxproj: Added SpinButtonElement.{cpp,h}
* accessibility/AccessibilitySpinButton.h: Replaced include file to SpinButtonElement.h from TextControlInnerElements.h
* html/TextFieldInputType.h: Added include file SpinButtonElement.h
* html/shadow/DateTimeEditElement.h: Replaced include file to SpinButtonElement.h from TextControlInnerElements.h
* html/shadow/SpinButtonElement.cpp: Removed code other than SpinButtonElement.
* html/shadow/SpinButtonElement.h: Removed code other than SpinButtonElement.
* html/shadow/TextControlInnerElements.cpp: Removed code of SpinButtonElement.
* html/shadow/TextControlInnerElements.h: Removed SpinButtonElement.
* rendering/RenderTheme.cpp: Added include file SpinButtonElement.h

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@125866 268f45cc-cd09-0410-ab3c-d52691b4dbfc